语法错误 (操作符丢失)怎么解决

我search.asp页面的代码如下：
 <%
                             dim shijian,nian,xueqi
                             nian1=request.form("nian1")
                             nian2=request.form("nian2")
                             xueqi=request.form("xueqi")
                             shijian=nian1&"-"&nian2&"年第"&xueqi&"学期"
                             Response.Write(shijian)
                           %>   
                           <%
                             Set rs1=Server.CreateObject("ADODB.RecordSet")
                             rs1.Open "select id from [time] where time=" &shijian,conn,1,1
                             if rs1.recordcount<>0 then
                                id=int(request("id"))
                             else id="没有对应内容"
                             end if
                             Response.Write(id)
                           %>
出现的错误提示如下：
Microsoft JET Database Engine (0x80040E14)
语法错误 (操作符丢失) 在查询表达式 'time=1-1年第1学期' 中。

请大家帮忙改一下，很急的，谢谢！