UPDATE 语句的语法错误???帮帮我！

Microsoft OLE DB Provider for ODBC Drivers (0x80040E14)
[Microsoft][ODBC Microsoft Access Driver] UPDATE 语句的语法错误。
/alaud/gq3/invest/Businessmd.asp, 第 62 行

 1   
 2Dim strUpdate,rsUpdate,strBusi,rsBusi   
 3  
 4If Session("userid")= "" then Response.Redirect "../login.asp?link=business/businessmd.asp?messageid="&Request.QueryString("messageid")   
 5If Request.QueryString("step")="modify" then   
 6if Request.Form("linkUrl")="http://" then   
 7strURL=""   
 8else   
 9strURL=Request.Form("linkUrl")   
10end if   
11  
12strUpdate="Update Business set type="&Request.Form("typeid")&",title='"&Request.Form("title")&"',keyword='"&Request.Form("keyword")&"',content='"&Request.Form("content")&"',other='"&Request.Form("other")&"',msgdate='"&Cstr(Formatdatetime(date,1))&"',linkUrl='"&strURL&"' where messageid="&Request.QueryString("messageid")   
13  
14Conn.Execute(strUpdate)   
15  
16

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用response.write strUpdate
把strUpdate写出来检查一下语法
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where messageid="&Cint(Request.QueryString("messageid"))

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把数据库表的所有字段设为可以为空，文本类型。看看一下，然后再改
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Request.Form("typeid")的值有可能为空吗？