建设工程合同制度:转SQL后出现的问题 - Microsoft OLE DB Provider for ODBC Drivers (0x80040E14)

请高人指点

错误类型：
Microsoft OLE DB Provider for ODBC Drivers (0x80040E14)
[Microsoft][ODBC SQL Server Driver][SQL Server]Incorrect syntax near the keyword 'and'.
/ceshi/atmo/jszx.asp, 第 565 行

代码如下:

sql="select discount_value from shop_discount where discount_begin_value<"&sumvalue&" and discount_end_value>="&sumvalue

'response.write ("<hr>")
'response.write sql
set myrs=server.CreateObject("adodb.recordset")
myrs.open sql,conn,3,3
if not myrs.bof and not myrs.eof then
discount_value=myrs("discount_value")
end if
'response.write ("<hr>")
'response.write discount_value
myrs.close
set myrs=nothing

错误代码是 :

sql="select discount_value from shop_discount where discount_begin_value<"&sumvalue&" and discount_end_value>="&sumvalue

注解: sumvalue 这个是 提取积分的. 请问为什么失败? 我在 access数据库下运行没有问题. 转换到 SQL后. 出错. 请高人指点.
代码上半段 :
<%
case "ok"
sumvalue=0
discount_value=1
sql="select sum((zonger)*discount) as sumvalue from shop_action where username='"&request.cookies("snsn")("username")&"'"
set myrs=server.CreateObject("adodb.recordset")
myrs.open sql,conn,3,3
if not myrs.bof and not myrs.eof then
do while not myrs.bof and not myrs.eof
sumvalue=sumvalue+myrs("feiyong")
myrs.movenext
loop
end if
myrs.close
sql="select discount_value from shop_discount where discount_begin_value< " & sumvalue & " and discount_end_value >= " & sumvalue
response.write ("<hr>")
response.write sql
set myrs=server.CreateObject("adodb.recordset")
myrs.open sql,conn,3,3
if not myrs.bof and not myrs.eof then
discount_value=myrs("discount_value")
end if
'response.write ("<hr>")
'response.write discount_value
myrs.close
set myrs=nothing
.......