Read Only Def Value

I want to use only the edit page.

I will set the url to /edit.asp?editid1=sessionIDvalue
Once on the edit page i have a field called store. I want it be dumped and replaced with my own session value Store_Name

1. what is the correct url syntax for ?editid1=
   
2. in edit.asp what do I change to drop the existing value and pick up Store_Name instead?
   build 326
   Thanks
   
   Michael