ADD A SCROLLBAR FOR ASP.NET AJAX MODAL POPUP EXTENDER INSIDE SHAREPOINT VISUAL WEBPART

I am using the ModalPopUpExtender in Visual WebPart, I need to allow vertical scroll therefore, I set the Panel Property  ScrollBars=”Vertical” as shown:

But unfortunately, the scroll still not working !! as shown below:

Solution:

In the same Tag I added a Height property and set it to appropriate value like  (590px).

The scroll is now working properly.

Enjoy 

source  : https://blog.devoworx.net/2014/12/06/how-to-add-scrollbar-for-asp-net-ajax-modal-popup-extender-in-visual-webpart/