background worker in asp.net

I migrate my winforms crawler app to a asp.net web app and would like to know how to implement the background worker thread that I use for very long searches?

Another posting mentioned asynchronous pages but I am not sure if this would work or how to apply it. The search function that would run can sometimes run for a few days and I w开发者_开发百科ould like the user to have the option to perform other functions still.

Can this happen?

Several days??? Please don't put something like this in an ASP.NET application. Use a Windows NT service, a console application whatever but if you monopolize threads in an ASP.NET application for several days this application won't likely handle many users.