Help with Postback issue on Drop Down Lists

Hi, can someone help me with a postback issue on the following code. I basically have 2 dropdown lists, and i want to pass the selections on a querystring to another page. However, and I'm not using postback, and the values that get sent are always the first ones, regardless of what you select. I'm a real beginner, can someone please just show me how to fix this, I'm pulling my hair out.

Code:

<%@ Page Language="VB" ContentType="text/html" ResponseEncoding="iso-8859-1" EnableViewState="false" %> <%@ Import Namespace="System.Data.OleDb" %> <script runat="server" language="VB"> Dim objConn As New OleDbConnection("Provider=Microsoft.Jet.OleDb.4.0;" & "Data Source=C:\Clients\NYCF\website\database\nycf.mdb") Dim objCmd As OleDbCommand Dim objRdr As OleDbDataReader Sub Page_Load() objConn.Open() objCmd = New OleDbCommand("SELECT Specialty FROM tblSpecialty ORDER BY Specialty",objConn) objRdr = ObjCmd.ExecuteReader() ddlSpecialty.Datasource = objRdr ddlSpecialty.DataValueField = "Specialty" ddlSpecialty.DataTextField = "Specialty" ddlSpecialty.DataBind() ddlSpecialty.Items.Insert(0, new ListItem("- Please Select -")) objRdr.Close() objCmd = New OleDbCommand("SELECT DISTINCT City FROM tblDoctors ORDER BY City",objConn) objRdr = ObjCmd.ExecuteReader() ddlCity.Datasource = objRdr ddlCity.DataValueField = "City" ddlCity.DataTextField = "City" ddlCity.DataBind() ddlCity.Items.Insert(0, new ListItem("- Please Select -")) objRdr.Close() ObjConn.Close() End Sub Sub searchSubmit(s As Object, e As ImageClickEventArgs) Dim strQueryStr As String = "?City=" & Server.UrlEncode(ddlCity.SelectedItem.Text) & "&Specialty=" & Server.UrlEncode(ddlSpecialty.SelectedItem.Text) Response.Redirect("search_results.aspx" & strQueryStr) End Sub </script> <html> <body> <form runat="server"> <asp:DropDownList id="ddlSpecialty" runat="server"> <asp:DropDownList id="ddlCity" runat="server"> <asp:ImageButton id="btnSubmit" runat="server" AlternateText="Locate a Doc Now!" ImageUrl="images/button_search_submit.gif" OnClick="searchSubmit" /> </form> </body> </html>