created a button to open a intake form as an input to rest message

[chercm]

hi i have created a button on the incident form to open a form to request first name , last name and phone as an input variable to Rest message but when i click the button nothing happens . 

Client script : 

function openDellIntakeForm() {
var dialogClass = window.GlideModal ? GlideModal : GlideDialogWindow;
var dialog = new dialogClass({
title: 'Dell Intake Form',
url: 'ui_page.do?sys_id=ef48652e476246107c2ba09f016d43b2' // Replace with your UI page sys_id
});
dialog.render();
}

UI action : 

• Name: Enter "Open Dell Ticket Form".
• Table: Select "Incident" (or the appropriate table where you want the UI action to appear).
• Action Name: Enter "Open Dell Ticket Form".
• Client: Check this checkbox.
• Onclick: Enter openDellIntakeForm()
•  
• script. :
•  
• function openDellIntakeForm() {
  var dialogClass = window.GlideModal ? GlideModal : GlideDialogWindow;
  var dialog = new dialogClass('dell_intake_form');
  dialog.setTitle('Dell Intake Form');
  dialog.render();
  }