在ASP中，如何验证Email地址的合法性？代码是什么？

If instr(Request.Form("email"),"@")=0 or instr(Request.Form("email"),"@")=1 or instr(Request.Form("email"),"@")=len(email) then
Response.Write "<script language=javascript>alert('电子信箱格式填写不正确！');javascript:history.back();</script>"
Response.End
End If