How to return the view that caused the modal window?

Question

ASP.NET

Good afternoon. Tell me please. There are two views (index and details), they call one edit modal window, which, after adjusting the data, can save the data and return the view back through the post method, but there is a problem, post returns the index view, and you need to return the view that called the modal window. The question is how to determine programmatically what caused edit?