diff --git a/usr/local/www/system.php b/usr/local/www/system.php
index bebed656ec..2f8c31d8a9 100755
--- a/usr/local/www/system.php
+++ b/usr/local/www/system.php
@@ -241,7 +241,7 @@ if ($_POST) {
                 </tr>
                 <tr>
                   <td valign="top" class="vncell">webGUI port</td>
-                  <td class="vtable"> <input name="webguiport" type="text" class="formfld" id="webguiport" onchange="'webGUI port changes will take effect immediately after clicking save') "size="5" value="<?=htmlspecialchars($pconfig['webguiport']);?>">
+                  <td class="vtable"> <input name="webguiport" type="text" class="formfld" id="webguiport" onchange="alert('webGUI port changes will take effect immediately after clicking save');" size="5" value="<?=htmlspecialchars($pconfig['webguiport']);?>">
                     <br>
                     <span class="vexpl">Enter a custom port number for the webGUI
                     above if you want to override the default (80 for HTTP, 443