diff --git a/class/actions_subtotaltitle.class.php b/class/actions_subtotaltitle.class.php
index 9d9eb89..dc86d19 100755
--- a/class/actions_subtotaltitle.class.php
+++ b/class/actions_subtotaltitle.class.php
@@ -180,6 +180,8 @@ class ActionsSubtotalTitle extends CommonHookActions
             echo '<script type="text/javascript">'."\n";
             echo 'var subtotalTitleIsDraft = '.($this->isDraft ? 'true' : 'false').';'."\n";
             echo 'var subtotalTitleHasSections = '.($hasSections ? 'true' : 'false').';'."\n";
+            // AJAX-URL-Pfad für alle AJAX-Aufrufe
+            echo 'var subtotaltitleAjaxUrl = "'.dol_buildpath('/subtotaltitle/ajax/', 1).'";'."\n";
             // Grip-Bild-Pfad für Drag&Drop (wie Dolibarr es macht)
             echo 'var subtotalTitleGripUrl = "'.DOL_URL_ROOT.'/theme/'.$conf->theme.'/img/grip.png";'."\n";
             echo 'var subtotalTitleLang = {'."\n";
diff --git a/core/modules/modSubtotalTitle.class.php b/core/modules/modSubtotalTitle.class.php
index f117cf4..bf7088d 100755
--- a/core/modules/modSubtotalTitle.class.php
+++ b/core/modules/modSubtotalTitle.class.php
@@ -76,7 +76,7 @@ class modSubtotalTitle extends DolibarrModules
 		$this->editor_squarred_logo = '';					// Must be image filename into the module/img directory followed with @modulename. Example: 'myimage.png@subtotaltitle'
 
 		// Possible values for version are: 'development', 'experimental', 'dolibarr', 'dolibarr_deprecated', 'experimental_deprecated' or a version string like 'x.y.z'
-		$this->version = '1.0';
+		$this->version = '4.0';
 		// Url to the file with your last numberversion of this module
 		//$this->url_last_version = 'http://www.example.com/versionmodule.txt';
 
diff --git a/js/mark_line_orders.js b/js/mark_line_orders.js
index 63980f5..9a32afb 100755
--- a/js/mark_line_orders.js
+++ b/js/mark_line_orders.js
@@ -3,7 +3,7 @@ $(document).ready(function() {
     var factureId = getFactureId();
     if (!factureId) return;
 
-    $.get('/dolibarr/custom/subtotaltitle/ajax/get_line_orders.php', {
+    $.get(subtotaltitleAjaxUrl + 'get_line_orders.php', {
         facture_id: factureId
     }, function(response) {
         if (!response.success) return;
diff --git a/js/subtotaltitle.js b/js/subtotaltitle.js
index f23ba5c..23fc84d 100755
--- a/js/subtotaltitle.js
+++ b/js/subtotaltitle.js
@@ -1,6 +1,24 @@
 // DEBUG FLAG - true für Debug-Ausgaben, false für Produktiv
 var SUBTOTAL_DEBUG = false;
 
+// Fallback für AJAX-URL wenn nicht von PHP gesetzt (z.B. bei direktem JS-Include)
+if (typeof subtotaltitleAjaxUrl === 'undefined') {
+    // Versuche URL aus aktuellem Script-Pfad abzuleiten
+    var scripts = document.getElementsByTagName('script');
+    for (var i = 0; i < scripts.length; i++) {
+        var src = scripts[i].src || '';
+        if (src.indexOf('subtotaltitle') !== -1 && src.indexOf('/js/') !== -1) {
+            // Pfad: .../subtotaltitle/js/subtotaltitle.js -> .../subtotaltitle/ajax/
+            var subtotaltitleAjaxUrl = src.replace(/\/js\/.*$/, '/ajax/');
+            break;
+        }
+    }
+    // Letzter Fallback
+    if (typeof subtotaltitleAjaxUrl === 'undefined') {
+        var subtotaltitleAjaxUrl = '/custom/subtotaltitle/ajax/';
+    }
+}
+
 function debugLog(message) {
     if (SUBTOTAL_DEBUG) {
         console.log(message);
@@ -202,7 +220,7 @@ function cleanupOrphanedSubtotals() {
     var docInfo = getDocumentInfo();
     if (!docInfo.id) return;
 
-    $.post('/dolibarr/custom/subtotaltitle/ajax/cleanup_subtotals.php', {
+    $.post(subtotaltitleAjaxUrl + 'cleanup_subtotals.php', {
         facture_id: docInfo.id,
         document_type: docInfo.type
     }, function(response) {
@@ -333,7 +351,7 @@ function createNewSection() {
         function(title) {
             debugLog('Erstelle Section: ' + title + ' für ' + docInfo.type + ' ID ' + docInfo.id);
 
-            $.post('/dolibarr/custom/subtotaltitle/ajax/create_section.php', {
+            $.post(subtotaltitleAjaxUrl + 'create_section.php', {
                 facture_id: docInfo.id,
                 document_type: docInfo.type,
                 title: title
@@ -362,7 +380,7 @@ function moveSection(sectionId, direction) {
     var docInfo = getDocumentInfo();
     debugLog('🔄 Verschiebe Section ' + sectionId + ' ' + direction + ' (docType: ' + docInfo.type + ')');
 
-    $.post('/dolibarr/custom/subtotaltitle/ajax/move_section.php', {
+    $.post(subtotaltitleAjaxUrl + 'move_section.php', {
         section_id: sectionId,
         direction: direction,
         document_type: docInfo.type
@@ -402,7 +420,7 @@ function renameSection(sectionId, currentTitle) {
         function(newTitle) {
             debugLog('✏️ Benenne Section ' + sectionId + ' um zu: ' + newTitle);
 
-            $.post('/dolibarr/custom/subtotaltitle/ajax/rename_section.php', {
+            $.post(subtotaltitleAjaxUrl + 'rename_section.php', {
                 section_id: sectionId,
                 title: newTitle
             }, function(response) {
@@ -434,7 +452,7 @@ function deleteSection(sectionId) {
         function() {
             debugLog('🗑️ Lösche leere Section ' + sectionId);
 
-            $.post('/dolibarr/custom/subtotaltitle/ajax/delete_section.php', {
+            $.post(subtotaltitleAjaxUrl + 'delete_section.php', {
                 section_id: sectionId,
                 force: 0,
                 document_type: getDocumentType()
@@ -478,7 +496,7 @@ function deleteSectionForce(sectionId) {
                 function() {
                     debugLog('Force-Delete Section ' + sectionId + ' mit Produkten: ' + JSON.stringify(productIds));
 
-                    $.post('/dolibarr/custom/subtotaltitle/ajax/delete_section.php', {
+                    $.post(subtotaltitleAjaxUrl + 'delete_section.php', {
                         section_id: sectionId,
                         force: 1,
                         product_ids: JSON.stringify(productIds),
@@ -512,7 +530,7 @@ function insertEmptySections() {
 
     debugLog('📦 Lade alle Sections für ' + docInfo.type + ' ID ' + docInfo.id);
 
-    $.get('/dolibarr/custom/subtotaltitle/ajax/get_sections.php', {
+    $.get(subtotaltitleAjaxUrl + 'get_sections.php', {
         facture_id: docInfo.id,
         document_type: docInfo.type
     }, function(response) {
@@ -751,7 +769,7 @@ function saveCurrentOrder() {
     debugLog('🚀 Sende ' + updates.length + ' Updates...');
 
 	var docInfo = getDocumentInfo();
-	$.post('/dolibarr/custom/subtotaltitle/ajax/reorder_all.php', {
+	$.post(subtotaltitleAjaxUrl + 'reorder_all.php', {
 	    facture_id: getFactureId(),
 	    document_type: docInfo.type,
 	    new_order: JSON.stringify(updates)
@@ -775,7 +793,7 @@ function moveProductToSection(productId, sectionId, newLineOrder) {
     var lang = (typeof subtotalTitleLang !== 'undefined') ? subtotalTitleLang : {};
     debugLog('🚀 Verschiebe Produkt ' + productId + ' zu Section ' + (sectionId || 'FREI') + ' auf Position ' + newLineOrder);
 
-    $.post('/dolibarr/custom/subtotaltitle/ajax/move_product.php', {
+    $.post(subtotaltitleAjaxUrl + 'move_product.php', {
         product_id: productId,
         new_section_id: sectionId || 0,
         new_line_order: newLineOrder
@@ -904,7 +922,7 @@ function assignLastProductToSection(sectionId, factureId) {
     var docInfo = getDocumentInfo();
     debugLog('🎯 Weise neustes Produkt zu Section ' + sectionId + ' zu (docType: ' + docInfo.type + ')...');
 
-    $.post('/dolibarr/custom/subtotaltitle/ajax/assign_last_product.php', {
+    $.post(subtotaltitleAjaxUrl + 'assign_last_product.php', {
         facture_id: factureId,
         section_id: sectionId,
         document_type: docInfo.type
@@ -1127,7 +1145,7 @@ function insertLastSectionSubtotal() {
     // Hole Subtotal-ID aus Datenbank (oder erstelle ihn falls nötig)
     var docType = getDocumentType();
     $.ajax({
-        url: '/dolibarr/custom/subtotaltitle/ajax/check_subtotal.php',
+        url: subtotaltitleAjaxUrl + 'check_subtotal.php',
         method: 'GET',
         data: {
             section_id: sectionId,
@@ -1203,7 +1221,7 @@ function insertTextLines() {
 
     debugLog('📝 Lade Textzeilen für ' + docInfo.type + ' ID ' + docInfo.id);
 
-    $.get('/dolibarr/custom/subtotaltitle/ajax/get_textlines.php', {
+    $.get(subtotaltitleAjaxUrl + 'get_textlines.php', {
         facture_id: docInfo.id,
         document_type: docInfo.type
     }, function(response) {
@@ -1232,7 +1250,7 @@ function toggleSubtotal(sectionId, checkbox) {
     debugLog('🔢 Toggle Subtotal für Section ' + sectionId + ': ' + show + ', docType: ' + docType);
 
     $.ajax({
-        url: '/dolibarr/custom/subtotaltitle/ajax/toggle_subtotal.php',
+        url: subtotaltitleAjaxUrl + 'toggle_subtotal.php',
         method: 'POST',
         data: {
             section_id: sectionId,
@@ -1383,7 +1401,7 @@ function createTextLine() {
         function(text) {
             debugLog('Erstelle Textzeile für ' + docInfo.type + ' ID ' + docInfo.id);
 
-            $.post('/dolibarr/custom/subtotaltitle/ajax/create_textline.php', {
+            $.post(subtotaltitleAjaxUrl + 'create_textline.php', {
                 facture_id: docInfo.id,
                 document_type: docInfo.type,
                 text: text
@@ -1417,7 +1435,7 @@ function editTextLine(textlineId, currentText) {
         function(newText) {
             debugLog('✏️ Bearbeite Textzeile ' + textlineId);
 
-            $.post('/dolibarr/custom/subtotaltitle/ajax/edit_textline.php', {
+            $.post(subtotaltitleAjaxUrl + 'edit_textline.php', {
                 textline_id: textlineId,
                 text: newText
             }, function(response) {
@@ -1449,7 +1467,7 @@ function deleteTextLine(textlineId) {
         function() {
             debugLog('Lösche Textzeile ' + textlineId);
 
-            $.post('/dolibarr/custom/subtotaltitle/ajax/delete_textline.php', {
+            $.post(subtotaltitleAjaxUrl + 'delete_textline.php', {
                 textline_id: textlineId,
                 document_type: getDocumentType()
             }, function(response) {
@@ -1482,7 +1500,7 @@ function removeFromSection(productId) {
             var docType = getDocumentType();
             debugLog('Entferne Produkt ' + productId + ' aus Section (docType: ' + docType + ')');
 
-            $.post('/dolibarr/custom/subtotaltitle/ajax/remove_from_section.php', {
+            $.post(subtotaltitleAjaxUrl + 'remove_from_section.php', {
                 product_id: productId,
                 document_type: docType
             }, function(response) {
@@ -1560,7 +1578,7 @@ function deleteMassSelected() {
 
         showConfirmDialog('Letzte Warnung', '<div style="color:#c00;font-weight:bold;">' + msg2 + '</div>', function() {
             // Zweite Bestätigung OK - jetzt löschen
-            $.post('/dolibarr/custom/subtotaltitle/ajax/mass_delete.php', {
+            $.post(subtotaltitleAjaxUrl + 'mass_delete.php', {
                 line_ids: JSON.stringify(selectedIds),
                 facture_id: getFactureId(),
                 document_type: getDocumentType()
@@ -1740,7 +1758,7 @@ function linkToNearestSection(lineId) {
             debugLog('  AJAX Call: add_to_section.php');
 
             // AJAX Call zum Backend
-            $.post('/dolibarr/custom/subtotaltitle/ajax/add_to_section.php', {
+            $.post(subtotaltitleAjaxUrl + 'add_to_section.php', {
                 line_id: lineId,
                 section_id: targetSection.id,
                 document_id: docInfo.id,
diff --git a/js/subtotaltitle_sync.js b/js/subtotaltitle_sync.js
index 41a713d..3e38701 100755
--- a/js/subtotaltitle_sync.js
+++ b/js/subtotaltitle_sync.js
@@ -27,7 +27,7 @@ function syncToFacturedet(lineId, lineType) {
     var docType = getDocumentTypeForSync();
     debugLog('Document type: ' + docType);
 
-    $.post('/dolibarr/custom/subtotaltitle/ajax/sync_to_facturedet.php', {
+    $.post(subtotaltitleAjaxUrl + 'sync_to_facturedet.php', {
         action: 'add',
         line_id: lineId,
         line_type: lineType,
@@ -64,7 +64,7 @@ function removeFromFacturedet(lineId, lineType) {
             var docType = getDocumentTypeForSync();
             debugLog('Document type: ' + docType);
 
-            $.post('/dolibarr/custom/subtotaltitle/ajax/sync_to_facturedet.php', {
+            $.post(subtotaltitleAjaxUrl + 'sync_to_facturedet.php', {
                 action: 'remove',
                 line_id: lineId,
                 line_type: lineType,
@@ -148,7 +148,7 @@ function syncAllToFacturedet() {
                 var lineId = $(this).data('line-id');
                 var lineType = $(this).data('line-type');
 
-                $.post('/dolibarr/custom/subtotaltitle/ajax/sync_to_facturedet.php', {
+                $.post(subtotaltitleAjaxUrl + 'sync_to_facturedet.php', {
                     action: 'add',
                     line_id: lineId,
                     line_type: lineType,
@@ -207,7 +207,7 @@ function removeAllFromFacturedet() {
                 var lineId = $(this).data('line-id');
                 var lineType = $(this).data('line-type');
 
-                $.post('/dolibarr/custom/subtotaltitle/ajax/sync_to_facturedet.php', {
+                $.post(subtotaltitleAjaxUrl + 'sync_to_facturedet.php', {
                     action: 'remove',
                     line_id: lineId,
                     line_type: lineType,
@@ -258,7 +258,7 @@ function updateAllSubtotals() {
     $subtotals.each(function() {
         var lineId = $(this).data('line-id');
 
-        $.post('/dolibarr/custom/subtotaltitle/ajax/sync_to_facturedet.php', {
+        $.post(subtotaltitleAjaxUrl + 'sync_to_facturedet.php', {
             action: 'update_subtotal',
             line_id: lineId,
             document_type: docType
diff --git a/subtotaltitle.kdev4 b/subtotaltitle.kdev4
deleted file mode 100755
index add4938..0000000
--- a/subtotaltitle.kdev4
+++ /dev/null
@@ -1,4 +0,0 @@
-[Project]
-CreatedFrom=
-Manager=KDevCustomBuildSystem
-Name=subtotaltitle