how to enlarge image from gridview

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False"
            DataKeyNames="P_No" DataSourceID="SqlDataSource1"
            style="margin-left:115px" AllowPaging="True"
            onselectedindexchanged="GridView1_SelectedIndexChanged">
            <Columns>
                <asp:BoundField DataField="P_No" HeaderText="P_No" ReadOnly="True"
                    SortExpression="P_No" ItemStyle-BackColor="#FFFF66" ItemStyle-HorizontalAlign="Center" ItemStyle-VerticalAlign="Middle" HeaderStyle-BackColor="#EAEA00" />
                <asp:BoundField DataField="Model" HeaderText="Model" SortExpression="Model" ItemStyle-BackColor="#FFFF66" HeaderStyle-BackColor="#EAEA00" />
                <asp:BoundField DataField="Price(Php)" HeaderText="Price(Php)"
                    SortExpression="Price(Php)" ItemStyle-BackColor="#FFFF66" HeaderStyle-BackColor="#EAEA00" />
                <asp:BoundField DataField="ImageFilename" HeaderText="ImageFilename"
                    SortExpression="ImageFilename" ItemStyle-BackColor="#FFFF66" HeaderStyle-BackColor="#EAEA00" />

            <asp:TemplateField HeaderText="Images" HeaderStyle-BackColor="#EAEA00" >
               <ItemTemplate>
                   <!--<asp:Image ID="Image1" Height="50px" Width="60px" runat ="server" ImageUrl='<%#Eval("ImageFilename","~/Images/{0}") %>' /> -->
                   <asp:ImageButton ID="ImageButton1" runat="server" Height="50px" Width="60px" ImageUrl='<%#Eval("ImageFilename","~/Images/{0}") %>'  OnClientClick ="return abc();"  />
              </ItemTemplate>
           </asp:TemplateField>

           </Columns>
        </asp:GridView>

            <asp:SqlDataSource ID="SqlDataSource1" runat="server"
            ConnectionString="<%$ ConnectionStrings:DatabaseConnectionString %>"
            SelectCommand="SELECT * FROM [DevelopTbl]"></asp:SqlDataSource>