diff --git a/.gitignore b/.gitignore
index 3cb7175..4f9cced 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,7 +1,8 @@
 # General
 .DS_Store
+.swp
 
 # bundle
 Gemfile.lock
 vendor/
-.bundle
+.bundle
\ No newline at end of file
diff --git a/lib/history.rb b/lib/history.rb
index 8fc7ad7..2a9590d 100644
--- a/lib/history.rb
+++ b/lib/history.rb
@@ -39,9 +39,7 @@ def output_action_modal(action)
     <div class="modal" id="#{id}" aria-hidden="true" tabindex="-1">
       <div class="modal-dialog modal-dialog-scrollable">
         <div class="modal-content">
-          <div class="modal-body" id="#{id}Body">
-            (Something wrong)
-          </div>
+          <div class="modal-body" id="#{id}Body"></div>
           <div class="modal-footer">
             <form action="#{form_action}" method="post" id="#{id}Form">
               <input type="hidden" name="action" value="#{action}">
diff --git a/views/form.erb b/views/form.erb
index d0d817b..5b2751f 100644
--- a/views/form.erb
+++ b/views/form.erb
@@ -54,9 +54,7 @@
     <!-- Script Content Section -->
     <div class="col py-3 d-flex flex-column">
       <label id="label_<%= OC_SCRIPT_CONTENT %>" class="fw-semibold" for="<%= OC_SCRIPT_CONTENT %>"><%= @script_label %></label>
-      <textarea id="<%= OC_SCRIPT_CONTENT %>" name="<%= OC_SCRIPT_CONTENT %>" class="form-control mt-1 mb-3 flex-grow-1" tabindex="<%= @table_index %>" accesskey="s" oninput="ocForm.updateHeight(ocForm.scriptArea)" required>
-        (Something wrong)
-      </textarea>
+      <textarea id="<%= OC_SCRIPT_CONTENT %>" name="<%= OC_SCRIPT_CONTENT %>" class="form-control mt-1 mb-3 flex-grow-1" tabindex="<%= @table_index %>" accesskey="s" oninput="ocForm.updateHeight(ocForm.scriptArea)" required></textarea>
       <!-- Submit Button -->
       <% if @form_action == "confirm" || @form_action == "confirm-save" %>
       <button class="btn btn-primary d-block w-100" id="<%= SUBMIT_BUTTON %>" type="button" data-bs-toggle="modal" data-bs-target="#modal-<%= SUBMIT_CONFIRM %>" tabindex="<%= @table_index + 1 %>">
@@ -93,12 +91,35 @@
     </div>
   </div>
 </form>
+
 <script>
 var ocForm = ocForm || {};
 ocForm.scriptArea = document.getElementById('<%= OC_SCRIPT_CONTENT %>');
 ocForm.submitArea = document.getElementById('<%= SUBMIT_CONTENT %>');
 </script>
+
 <script src="form.js"></script>
+
+<%
+require "yaml"
+require "erb"
+require "pathname"
+
+app_root  = Pathname.new(__dir__).join("..").expand_path
+conf_path = app_root.join("conf.yml.erb")
+
+conf_hash =
+  if conf_path.exist?
+    rendered = ERB.new(conf_path.read).result(binding)
+    YAML.safe_load(rendered) || {}
+  else
+    {}
+  end
+
+# If scheduler is missing, this becomes "slurm"
+scheduler = conf_hash.fetch("scheduler", "slurm")
+%>
+
 <script>
 // Executes functions that should run once.
 ocForm.onceExec = function() {
@@ -157,9 +178,67 @@ document.addEventListener('keydown', function(event) {
   }
 });
 
+// Split text into shebang, header (scheduler directive lines lines) and body
+function splitText(text){
+    text = (text ?? '').toString();
+    const lines = text.split('\n');
+    let shebang = '';
+    const header = [];
+    const body = [];
+
+    // Choose a directive for the header depending on the scheduler selected in conf.yml.erb
+    const scheduler = "<%= scheduler.to_s %>".trim().toLowerCase();
+    let directive;
+    if (scheduler === "slurm") { directive = "#SBATCH"; }
+    else if (scheduler === "pbs" || scheduler === "pbspro" || scheduler === "torque") { directive = "#PBS"; }
+    else if (scheduler === "grid_engine" || scheduler === "sge") { directive = "#$"; }
+    else if (scheduler === "lsf") { directive = "#BSUB"; }
+    else { directive = "#SBATCH"; }
+
+    for (const line of lines) {
+      const trimmed = line.trim();
+      if (!shebang && trimmed.startsWith("#!")) { shebang = trimmed; }
+      else if (trimmed.startsWith(directive)) { header.push(trimmed); }
+      else if (body.at(-1)!="" || trimmed!="") { body.push(trimmed); }
+    }
+
+    if (body.length === 1 && body[0] === "") return { shebang, header, body: [] };
+
+    return { shebang, header, body }
+}
+
+// Rebuild script area content by replacing only the content of the header
+function rebuildWithSbatchHeader(currentText, headerText) {
+  const { shebang: currentShebang, header: currentHeader, body: currentBody } = splitText(currentText);
+  const { shebang: renderedShebang, header: renderedHeader, body: renderedBody } = splitText(headerText);
+
+  const finalShebang = renderedShebang ? renderedShebang : currentShebang || '';
+  const finalHeader = renderedHeader?.length>0 ? renderedHeader : currentHeader?.length>0 ? currentHeader : [];
+
+  const filteredRenderedBody = renderedBody.filter(item => item.trim() !== "");
+  const filteredCurrentBody  = currentBody.filter(item => item.trim() !== "");
+  let finalBody;
+  if (filteredRenderedBody.length === 0 && filteredCurrentBody.length === 0) { finalBody = []; }
+  else if (filteredCurrentBody.length>0) { finalBody = currentBody; } // Give priority to currentBody if not empty
+  else { finalBody = renderedBody; }
+  if (finalBody[0] === "") { finalBody.shift(); } // Remove first line if empty (it will be introduced if hasTopSection)
+  if (finalBody.at(-1) === "") { finalBody.pop(); } // Remove empty line at the end
+
+  const hasTopSection = (finalShebang?.trim()!=='') || (finalHeader.length>0);
+  const combined = [
+    ...(finalShebang ? [finalShebang] : []),
+    ...finalHeader,
+    ...(hasTopSection && finalBody.length>0 ? [""] : []),
+    ...finalBody
+  ];
+
+  return combined.join("\n");
+}
+
 ocForm.isFirst = true;
 ocForm.multiSelectDisabledIndexes = {};
 ocForm.updateValues = function(fromId) {
+  console.group("updateValues");
   let scriptValues = [];
   let submitValues = [];
   ocForm.initDynamicWidget(fromId);
@@ -170,25 +249,32 @@ ocForm.updateValues = function(fromId) {
     ocForm.onceExec();
     ocForm.updateScriptContents(scriptValues);
     ocForm.updateSubmitContents(submitValues);
-    ocForm.scriptArea.value = ocForm.isScriptCache() ? ocForm.loadScriptCache() : Object.values(scriptValues).join('\n');
+
+    // Overwrite of script textarea (first run)
+    const newHeaderFirst = Object.values(scriptValues).join('\n');
+    const baseTextFirst = ocForm.isScriptCache() ? ocForm.loadScriptCache() : (ocForm.scriptArea.value || '');
+    ocForm.scriptArea.value = rebuildWithSbatchHeader(baseTextFirst, newHeaderFirst);
+
+    // Overwrite of submit textarea (first run)
     ocForm.submitArea.value = ocForm.isSubmitCache() ? ocForm.loadSubmitCache() : Object.values(submitValues).join('\n');
   }
+
   else {
     ocForm.updateScriptContents(scriptValues);
     ocForm.updateSubmitContents(submitValues);
-    ocForm.scriptArea.value = Object.values(scriptValues).join('\n');
+
+    // Overwrite of script textarea (subsequent runs)
+    const newHeaderNext = Object.values(scriptValues).join('\n');
+    ocForm.scriptArea.value = rebuildWithSbatchHeader(ocForm.scriptArea.value || '', newHeaderNext);
+
+    // Overwrite of submit textarea (subsequent runs)
     ocForm.submitArea.value = Object.values(submitValues).join('\n')
   }
 
-  // Add a newline if it is not the last one
-  //if (!ocForm.scriptArea.value.endsWith('\n')){
-  //  ocForm.scriptArea.value += '\n';
-  //}
-  //if (!ocForm.submitArea.value.endsWith('\n')){
-  //  ocForm.submitArea.value += '\n';
-  //}
+  // Height adjustments
   ocForm.updateHeight(ocForm.scriptArea);
   ocForm.updateHeight(ocForm.submitArea);
+  console.groupEnd();
 };
 
 window.onload = ocForm.updateValues();