Shopping Cart Error.. Needs help!

Hmm.. I don't know what is wrong!

Compiler Error Message: BC30456: 'Delete_Item' is not a member of 'ASP.ShoppingCart_aspx'.

Source Error:
Line 13: <asp:TextBox id="tb_Quantity" style="Z-INDEX: 101; LEFT: 32px; POSITION: absolute; TOP: 288px"
Line 14: runat="server"></asp:TextBox>
Line 15: <asp:DataGrid id="dg" style="Z-INDEX: 102; LEFT: 200px; POSITION: absolute; TOP: 112px" runat="server" OnDeleteCommand="Delete_Item">
Line 16: <Columns>
Line 17: <asp:ButtonColumn ButtonType="LinkButton" CommandName="Delete" Text="Remove Item" /
Source File: c:\inetpub\wwwroot\shoppingCart\ShoppingCart.aspx Line: 15

The complete source is at this url:
http://www.twistedhopes.com/bbs/index.php?s=93970ee88bb281e8d04f75af7d6f713a&act=Attach&type=post&id=72301

Anyone can help? Thanks..Seems to me the Event Name is 'Delete_items' NOT 'Delete_item'
Erm.. what can I do to fix it?