title: How to update an onscreen price without refreshing page when using DDL
body: <p>I am setting up a page to allow users to create their own pool cues. As they select a feature they want on their cue from a dropdown list it needs to update the price onscreen but not refresh the whole page. I'm guessing I would use an update panel ? Not sure where and how to add it. The selected value passed to the VB code is the extra price to pay (Eg: £10 extra for a jointed cue). Here's what I have so far..</p>
  
  <p>FRONT END</p>
  
  <pre><code>&lt;asp:DropDownList ID="ddlJoint" runat="server" AutoPostBack="true" RenderMode="Partial" style="margin-bottom:10px" height="33px" font-size="1.6em"  OnSelectedIndexChanged="ddlJoint_SelectedIndexChanged"&gt;
      &lt;asp:ListItem Value=""&gt;Cue Joint:&lt;/asp:ListItem&gt;
      &lt;asp:ListItem Value="10"&gt;3/4 Join&lt;/asp:ListItem&gt;
      &lt;asp:ListItem Value="0"&gt;One Piece&lt;/asp:ListItem&gt;
  &lt;/asp:DropDownList&gt;
  &lt;br&gt;
  &lt;asp:Label ID="lblTotal" runat="server" Text="Price:"&gt;&lt;/asp:Label&gt;
  </code></pre>
  
  <p>VB</p>
  
  <pre><code>Protected Sub ddlJoint_SelectedIndexChanged(sender As Object, e As System.EventArgs)
     session("joint") = ddlJoint.SelectedValue
     session("total") = session("joint") + session("tip")
     lblTotal.Text = session("total") + 180
  End Sub
  </code></pre>