How to connect SharePoint 2010 list to Telerik RadGrid

I want to populate a RadGrid with SharePoint 2010 list data. I cannot figure out how this is accomplished.

Here is my ASPX page:

<SPWebControls:SPDataSource runat="server" ID="dsclientmatter" DataSourceMode="ListItem" UseInternalName="true">
  <SelectParameters>
      <asp:Parameter Name="WebUrl" DefaultValue="/configuration/" />
      <asp:Parameter Name="ListID" DefaultValue="4056449D-1884-4C79-AAAD-CD0ABEB2F854" />
      <asp:Parameter Name="ListItemID" DefaultValue="1" />
  </SelectParameters>
</SPWebControls:SPDataSource>
 
<telerik:RadGrid ID="RadGrid1" runat="server" GridLines="None" ShowStatusBar="true" PageSize="7" AllowPaging="True" DataSourceID="dsclientmatter" >
    <ClientSettings>
        <Selecting AllowRowSelect="True" />
    </ClientSettings>
<MasterTableView datasourceid="">
<CommandItemSettings ExportToPdfText="Export to PDF"></CommandItemSettings>
 
<RowIndicatorColumn Visible="True" FilterControlAltText="Filter RowIndicator column">
<HeaderStyle Width="20px"></HeaderStyle>
</RowIndicatorColumn>
 
<ExpandCollapseColumn Visible="True" FilterControlAltText="Filter ExpandColumn column">
<HeaderStyle Width="20px"></HeaderStyle>
</ExpandCollapseColumn>
 
<EditFormSettings>
<EditColumn FilterControlAltText="Filter EditCommandColumn column"></EditColumn>
</EditFormSettings>
</MasterTableView>
 
<FilterMenu EnableImageSprites="False"></FilterMenu>
</telerik:RadGrid>

Here is my code-behind:

protected void Page_Load(object sender, EventArgs e)
        {
            SPSite site = new SPSite("http://abcdev");
             
            using (SPWeb web = site.OpenWeb())
            {
                SPList clientlist = web.Lists.TryGetList("clientmatter");
                DataTable dt = new DataTable();
                SPQuery query = new SPQuery();
                query.ViewFields = "<Where><Eq><FieldRef Name='clientid'/><Value Type='Text'>12345</Value></Eq></Where>";
                SPListItemCollection items = clientlist.GetItems(query);
                if(items != null)
                {
                    if(items.Count > 0)
                    {
                        dt = items.GetDataTable();                       
                        GridView1.DataSource = dt;
                        GridView1.DataBind();
                         
                    }
                }
            }
        }

I don't know if this is the best way to start, but I do know something is wrong because I cant render any data. Plus, I don't understand why by RadGrid ID will not compile. I get an error stating "The name 'GridView1' does not exist in the current context". Why. That is the ID of my RadGrid.

My end goal is to create a RadGrid that I can filter by individual columns, such as: name, client#, topic, etc. I am not sure if the filtering allows for multiple entries, but I would like to be able to filter on more than one criteria. Also, wildcard searches are very important.

Thank you for the help!