I'd like an ASP.button instead of the user pressing "Enter" on the textbox

 I have a textbox, the user enters in data into the textbox and presses enter a gridview shows up with information about the data in the textbox. Instead of pressing enter after putting data in the textbox, I would like a "Search" button, so the user would enter data then press "Search" the "Serach" button would trigger the Gridview to open. Can someone help me out? Here is my code in VB:
 
<asp:TextBox runat="server" id="TextBox1" Font-Names="Trebuchet MS" Font-Size="X-Small"></asp:TextBox>
         &nbsp;<asp:Button runat="server" Text="Search" id="Button1" />&nbsp;&nbsp;
    
    <span>&nbsp;<input type="button" onClick="myPopup2()" value="Help"></span>&nbsp;&nbsp;&nbsp; ...