>>>Hi,
>>>
>>>I want to create an ASP.NETpage that would be shown as a pop-up/modal form over the existing page. This ASP.NET pop-up form will be used when user clicks on Forget Password link to recover his/her password. The ASP.NET pop up form will show text, email address textbox, and Submit button. I have seen sites where such a form is shown over the existing page and I would like to duplicate this look.
>>>
>>>So, say I create such a small (relatively) ASP.NET page; how do I show it over the existing page?
>>>
>>>TIA
>>
>>If you're prepared to dive into angular/bootstrap I use the ui.bootstrap.modal. Scroll down here : http://angular-ui.github.io/bootstrap/
>
>I am ready to "dive" into angular but no time right now. I need to have these pages/changes fairly quickly. I do use bootstap however (without angular). So I will bookmark this link for the future. Thank you.

For HTML5 you could look at the standard HTMLDialogElement which might be sufficient : https://developer.mozilla.org/en-US/docs/Web/API/HTMLDialogElement

But browser support is patchy :-{