Controlling Asysn Web Service c#

Question

I am trying to do the following: I have an aspx page which displays a form for user to input data. They click ok and this runs a web service asynchronously to insert the data. I now want to load up another aspx page to display other data to the user. When this page has loaded I would then go off and check if the web service is complete and if yes display a message on the just loaded 2nd page. I know how to check if the service call is finished in the first page but don't know if it is possible to do from this newly loaded second page? Thanks for any help in advance.