Gridview TemplateField help.

I have a Gridview. I have a button in my first column, that I need to do a custom tasks.
The code for the button looks like this:

1 <asp:TemplateField>
2 <ItemTemplate>
3 <asp:ImageButton runat="server" ID="ChangeButton" CommandName="change" ImageUrl="~/Images/tool.png"
4 OnClientClick="if (!window.confirm('This will r ...