关于DateDiff函数

[jiangpingchang]

Dim userid,username,userrename,PayDate,StartDate,FinishDate
userid=rs1("userid")
username=rs1("username")
userrename=rs1("userrename")
PayDate=rs1("PayDate")
StartDate=rs1("StartDate")
FinishDate=rs1("FinishDate")
if DateDiff("s",StartDate," & SqlNowString & ")<1 then
response.redirect("pay.asp")
else response.redirect("bofang.asp?id='&id&'")
end if

老是报错
Microsoft VBScript 运行时错误 错误 '800a000d'

类型不匹配: '[string: " & SqlNowString & "]'

/pay/judge.asp，行 31


大侠帮忙看看怎么回事

[vrhero]

if DateDiff("s",StartDate, SqlNowString) <1 then

语法错误...

ps:好几年没摸ASP了...