Transfer TextBox.Text from webForm1.aspx to Global.asax Session_End

Question

I generate a XML file on an incrementing variable on Session_Start. I load the file path into an invisible ServerSide textBox. I want to delete this XML file when the Sessions Ends. How do I transfer the path to the Global.asax file in order to utilize the Session_End method? The end result is to only delete that file which was created specific to the Ending Session.