How to add pop-up message that the form is not available

if i want to set a pop up window to let know about the form is close, and how to set thanks

Hi,

Did you mean you wanted the pop-up message to happen when a link or the page is loaded in your website?

From what I understand so far, it seems you want the 'Form Not Available' message to be a pop-up message. Perhaps this can be achieve already outside jotform.  You can probably just add a pop-up using script in your website that will be triggered when a link or URL is click.

Share to us also the URL of your website where you used the jotform, and we will check further what we can suggest.

Thanks.