GridView Search Not Working

I am trying to create a textbox and button to search my gridview, however, it will not work..my code is below
<asp:SqlDataSource ID="SQLlistsel" runat="server" ConnectionString="<%$ ConnectionStrings:LI %>" ProviderName="<%$ ConnectionStrings:LI.ProviderName %>" SelectCommand="SELECT [LOCATIONID], [LOCNM], [STATUS] FROM [LOCATIONS]" FilterExpression="LOCATIONID LIKE '{0}'"> <FilterParameters> <asp:ControlParameter Name="STATUS" ControlID="txtSearch" PropertyName="Text" Type="Int32" /> </FilterParameters> </asp:SqlDataSource> <asp:ModalPopupExtender ID="mpe" runat="server" BehaviorID="popup1" PopupControlID="pnlPopup" BackgroundCssClass="modalBackground" TargetCont ...