ASP 提示非法赋值的解决方法

<%
'删除小类信息
sub delbuy()
id=clng(Request.QueryString("id"))
Set book=server.createobject("adodb.recordset")
        SQLstr="delete d_31 where id="&id&""
        conn.Execute SQLstr
        set book=nothing
        conn.close
        set conn=nothing
%>
<SCRIPT LANGUAGE=vbscript>
<!--
msgbox("删除成功!")
window.location.href="buySoScan.asp"
-->
</SCRIPT>
<%
end sub
%>

SQLstr="delete d_31 where id="&id&""
conn.Execute

dim sqlssqls = "delete from d_31 where id=" & clng(id)
conn.Execute(sqls)