ASP Overflow program need to be solved.

I have a website written by ASP and using MS SQL server, everything runs fine for years, but recently there is a overflow problem shown up as follows: ======== Microsoft VBScript runtime error '800a0006' Overflow: '[login to view URL]' /[login to view URL], row 500 ======== I guess it's a stack overflow problem, so I changed those int field to bigint, but it still don't work out. But I can update the old records by the asp file, just currently new record so above overflow problem. I wonder if anyone can help on this, thanks.