you must be kidding, try (select a state, then click on submit button)
<form runat=server>
        <asp:DropDownList id="StateList" runat="server">
          <asp:ListItem>CA</asp:ListItem>
          <asp:ListItem>IN</asp:ListItem>
          <asp:ListItem>KS</asp:ListItem>
          <asp:ListItem>MD</asp:ListItem>
</asp:DropDownList>
     
<asp:button Text="Submit" OnClick="SubmitBtn_Click" runat=server/> 
</form><script language="C#" runat="server">
void SubmitBtn_Click(Object sender, EventArgs e) 
{
  Response.Write("***"+ StateList.SelectedIndex +":" + StateList.SelectedItem.Text+"***");
}
</script>