How to search data from datalist using search button?

<asp:DataList ID="DataList1" runat="server" DataKeyField="ProductID" 
        DataSourceID="SqlDataSource1" onitemdatabound="use" BackColor="White" 
        EmptyDataText="Please Select Category."
           BorderColor="#E7E7FF" BorderStyle="None" BorderWidth="1px" CellPadding="3" 
           GridLines="Horizontal" RepeatColumns="3" RepeatDirection="Horizontal" 
        Height="534px" Width="720px" style="text-align: center; color: #000000;">
        <AlternatingItemStyle BackColor="White" />
        <FooterStyle BackColor="#B5C7DE" ForeColor="#4A3C8C" />
        <HeaderStyle BackColor="#4A3C8C" Font-Bold="True" ForeColor="#F7F7F7" />
        <ItemStyle BackColor="White" ForeColor="#4A3C8C" />
         <ItemTemplate>
            <asp:ImageButton ID="btnFileImg" runat="server" Height="100px" Width="80px" ImageUrl='<%# Eval("filename") %>'  PostBackUrl='<%# Eval("ProductID", "ProductDetails.aspx?ProductID={0}") %>' />
            <asp:Label ID="ImageUrlLabel" runat="server" Text='<%# Eval("filename") %>' Visible="False"></asp:Label><br />
    <br />
            <a href='ProductDetails.aspx?productID=<%# Eval("ProductID") %>' style="font-size: 15px; color: black">
            <asp:Label ID="NameLabel" runat="server" Text='<%# Eval("productName") %>'/><br />
            </a>
            Price: 
            <asp:Label ID="PriceLabel" runat="server" Text='<%# Eval("price") %>' />

        </ItemTemplate>
        <SelectedItemStyle BackColor="#738A9C" Font-Bold="True" ForeColor="#F7F7F7" />
    </asp:DataList>

<asp:TextBox ID="txtSearch" runat="server"></asp:TextBox>
    <asp:Button ID="Button1" runat="server" Text="Search" />

How can I search Product Name or Brand using Textbox and search button?