从数据库中动态选取下拉列表的方法

有一页填表的页面，其中有几个下拉表单是通过一个表的某个字段动态
生成，比如省下面的城市名，希望选择某一个省即可自动在另一下拉表
单内生成城市名，.....然后提交给asp处理加入到另外一个表内。

<form name=f1 METHOD="POST">
<%
OpenDB objConn, "xxxx"
Set RSClass = objConn.Execute("SELECT * FROM class Order by fldClass")
If RSClass.EOF Then
Response.Write "没有记录。<BR>"

Else

Response.Write "<SELECT NAME=""class"" style=""FONT-SIZE: 9pt"" SIZE=10" & _
" ONCHANGE=""classselected(this);"" >"
sJavaScript = "function classselected(elem){" &_
vbCrlf & _
"for (var i = document.f1.sort.options.length; i >= 0; i--){" & vbCrlf & _
"document.f1.sort.options[i] = null;" & _
vbCrlf
Do Until RSClass.EOF
If sLastClass <> RSClass("fldClass") Then
sLastClass = RSClass("fldClass")
Response.Write "<OPTION VALUE=" & RSClass("fldID") & ">" & sLastClass & "</OPTION>"
sJavaScript = sJavaScript & "}" & vbCrlf & _
"if (elem.options[elem.selectedIndex].value==" & _
RSClass("fldID") & "){" & vbCrlf
End If
sJavaScript = sJavaScript & _
"document.f1.sort.options[document." & _
"f1.sort.options.length] = new Option('" & _
RSClass("fldSort") & "','" & RSClass("fldID") & "');" & _
vbCrlf
RSClass.MoveNext
Loop
Response.Write "</SELECT>"
Response.Write "<SELECT NAME=""sort"" style=""FONT-SIZE: 9pt"" SIZE=10>"
Response.Write "<OPTION>[请选择]</OPTION>"
Response.Write "</SELECT>"

sJavaScript = sJavaScript & vbCrlf & "}" & vbCrlf & "}" & vbCrlf
Response.Write "<SCR" & "IPT LANGUAGE=""JavaScript"">" & vbCrlf
Response.Write sJavaScript & vbCrlf & "</SCR" & "IPT>" & vbCrlf
End If
RSClass.Close
Set RSClass = Nothing%>
</form>