[code snippets at the end]

I have a page that allows the user to search a DB by querying one of 3
fields. When results are returned, I want the user to be able to click a
value in one of three columns (that directly relate to the 3 searchable
fields) and have the page postback and requery given the selected criterion.
For example, the user searches for retainer #1, which has a Tip Width of 5.
So he clicks on the 5 and it searches again for all retainers that have a
similar Tip Width.

To achieve this, I have a Gridview with several BoundFields and one
LinkButton (within a Template) for each of the 3 searcable columns. So far
so good...

I'm strugglin however to make the next move. I don't know how to code it so
that by clicking on a LinkButton, the SearchVal field is repopulated with
the selected value, the SearchType radio button is set to the appropriate
type, and the btnSearch_Click sub is called. I'm not sure which event of
which control I need to create a handler for, nor what I do thereafter.

I imagine this is quite simple, but it's my first proper ASP.NET
application, so I'm still rather out of my depth. I've searched for
examples, but I haven't found one that matches this scenario, though there
have been plenty of hints that this is a commonly used approach.

Can anyone point me in the rifght direction?

Thanks in advance.

CJM

Snippets:

<fieldset>
   <legend>Search Criteria</legend>
   <table id="search">
    <tr>
     <td>Search Value:</td>
     <td><asp:TextBox ID="SearchVal" TextMode="SingleLine" MaxLength="20"
runat="server" Columns="20" /></td>
     <td><asp:RadioButton GroupName="SearchField" ID="rdoRetainer"
Text="Retainer No:" Checked runat="server" /></td>
    </tr>
    <tr>
     <td colspan="2">&nbsp;</td>
     <td><asp:RadioButton GroupName="SearchField" ID="rdoTipWidth"
Text="Tip Width:" runat="server" /></td>
    </tr>
    <tr>
     <td>&nbsp;</td>
     <td><asp:Button ID="btnSearch" Text="Search" runat="server" /></td>
     <td><asp:RadioButton GroupName="SearchField" ID="rdoFlange"
Text="Ideal Flange" runat="server" /></td>
    </tr>
   </table>
   <asp:Label ID="lblFeedback"  Text="feedback" runat="server"/>
</fieldset>

<asp:GridView ID="grdRetainers" AutoGenerateColumns="False" runat="server">
   <Columns>
    <asp:TemplateField HeaderText="Retainer">
     <ItemTemplate>
      <asp:LinkButton CommandName="ViewRetainer" ID="btnRetainer"
runat="server"><%#Eval("RetNo")%></asp:LinkButton>
     </ItemTemplate>
    </asp:TemplateField>
    <asp:TemplateField HeaderText="Tip Width">
     <ItemTemplate>
      <asp:LinkButton CommandName="SearchByTipWidth" ID="btnTipWidth"
runat="server"><%#Eval("TipWidth")%></asp:LinkButton>
     </ItemTemplate>
    </asp:TemplateField>
    <asp:BoundField HeaderText="Thick" DataField="Thickness"  />
    <asp:BoundField HeaderText="Depth" DataField="Depth" />
    <asp:BoundField HeaderText="Style" DataField="Style" />
    <asp:BoundField HeaderText="Angle" DataField="InternalAngle" />
    <asp:BoundField HeaderText="Dev Width" DataField="DevelopedWidth" />
    <asp:TemplateField HeaderText="Flange">
     <ItemTemplate>
      <asp:LinkButton o OnCommand="" CommandName="SearchByFlange"
ID="btnFlange" runat="server"><%#Eval("IdealFlangeTip")%></asp:LinkButton>
     </ItemTemplate>
    </asp:TemplateField>
   </Columns>
  </asp:GridView>

Protected Sub btnSearch_Click(ByVal sender As Object, ByVal e As
System.EventArgs) Handles btnSearch.Click

 Dim oConn As New SqlConnection("..etc...")
 Dim oCmd As New SqlCommand
 Dim drRetainers As SqlDataReader

 oConn.Open()
 With oCmd
  .Connection = oConn
  .CommandType = Data.CommandType.StoredProcedure
  .Parameters.Clear()

  If rdoRetainer.Checked Then
   .CommandText = "mnd_ListRetainersByRetNo"

   .Parameters.Add("RetainerNo", Data.SqlDbType.VarChar, 10).Value =
SearchVal.Text
  End If
  If rdoTipWidth.Checked Then
   'lblFeedback.Text = lblFeedback.Text & " 1"
   .CommandText = "mnd_ListRetainersByTipWidth"
   .Parameters.Add("TipWidth", Data.SqlDbType.VarChar, 10).Value =
SearchVal.Text
  End If
  If rdoFlange.Checked Then
   .CommandText = "mnd_ListRetainersByFlange"
   .Parameters.Add("Flange", Data.SqlDbType.VarChar, 10).Value =
SearchVal.Text
  End If
 End With

 drRetainers = oCmd.ExecuteReader
 With grdRetainers
  'lblFeedback.Text = lblFeedback.Text & " 2"
  .DataSource = drRetainers
  .DataBind()
  .GridLines = GridLines.None
  .CellSpacing = 1

 End With

 oConn.Close()
 drRetainers.Close()