How to pass value of a variable from Generic handler to my .aspx page

You'll need to provide some context such as what calls what and how, but it's unlikely you'll be able to do this as the ashx and aspx will be on separate requests and can't communicate to each other. You'll probably need to do the db insert in your handler, or if your ashx is called via js on an aspx page then do some work there to record the value. Without knowing more about your current setup it's hard to suggest anything specific.