Using LIKE And Wild Cards In Form Query

Hi,

I am using Visual Studio 2005. I am trying to create a ASP.net website and use a web form to get the results of an enquiry. It is almost the same as the presentation video on this website called "How to Create Data Driven Website", but I have added a new twist to it.  I want to use the "LIKE" instead of "=" in my SQL statement and I want to use wild cards in the parameter value that I enter.

<form id="form1" runat="server">
    <div>
        &nbsp;<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>

<%
        dim str as string = "%" & textbox1.text & "%"
        </%>
        <asp:TextBox ID="TextBox2" runat="server" Visible="False" Text=str></asp:TextBox>
        <asp:Button ID="Button1" runat="server" Text="Submit" Width="87px" BackColor="Khaki" ForeColor="Navy" PostBackUrl="~/Default.aspx" />

and the ControlID of the Datagrid will take in the value of "TextBox2" instead of "TextBox1" as so:

   <SelectParameters>
                <asp:ControlParameter ControlID="TextBox2" DefaultValue="SO06000001" Name="SO" PropertyName="Text"
                    Type="String" />

 However the syntax above does not work. May I ask what is the correct syntax?

Thanks.

Peter