diff --git a/equipments_mass_update.php b/equipments_mass_update.php
index d727aa8..8324e53 100644
--- a/equipments_mass_update.php
+++ b/equipments_mass_update.php
@@ -226,7 +226,7 @@ if ($_SESSION['permission'] == 3 || $_SESSION['permission'] == 4){
                 <div class="order-detail">
                 <textarea id="excel_data" name="excel_data" onkeydown="countLines()" style="width:100%;height:150px;" placeholder="'.$paste_excel_1.'&#10;'.$paste_excel_2.'"></textarea>
                 </div>
-                <input type="submit" value="'.$button_apply.'" onclick="return confirm(\''.$mass_update_confirm_message.'\')" class="btn">
+                <input type="submit" id="mass_update_submit" value="'.$button_apply.'" onclick="return confirm(\''.$mass_update_confirm_message.'\')" class="btn">
             ';
 $view .='              
             </div>
@@ -256,11 +256,28 @@ echo $view;
 
 echo '
 <script>
+
 function countLines(){ 
+    let button = document.getElementById("mass_update_submit");
     var text = document.getElementById("excel_data").value.trim(); 
     var lines = text.split(/\r|\r\n|\n/);
     var count = lines.length;
     document.getElementById("count").innerHTML = lines.length;
+
+    function checkIfDuplicateExists(arr) {
+        return new Set(arr).size !== arr.length
+    }
+
+    if (checkIfDuplicateExists(lines) == true){
+        var lines = [...new Set(lines)];
+        var count = lines.length;
+        document.getElementById("count").innerHTML = lines.length;
+        button.disabled = true;
+        button.style.background="#e3e4e6";
+    } else {
+        button.disabled = false;
+        button.style.background="#4a79b4";
+    }
 }
 </script>
 ';