cannot fire GridView1_RowCommand event when clicking delete button

HI, I am trying to delete a record in gridview via a button. Not sure why GridView1_RowCommand never get fired when I click on delete button...... any idea. thanks... bob <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataKeyNames="Id" OnRowDeleting="GridView1_RowDeleting" OnRowDeleted="GridView1_RowDeleted" OnRowEditing="GridView1_RowEditing" OnRowUpdated="GridView1_RowUpdated" OnRowUpdating="GridView1_RowUpdating" OnSelectedIndexChanged="GridView1_SelectedIndexChanged" OnSelectedIndexChanging="GridView1_SelectedIndexChanging" OnRowCommand="GridView1_RowCommand" OnRowCreated="GridView1_RowCreated" OnRowDataBound="GridView1_RowDataBound" OnDataBinding="GridView1_DataBinding" OnDataBound="GridView1_DataBound" OnRowCancelingEdit="GridView1_RowCancelingEdit"> <Columns> <asp:TemplateField> <HeaderTemplate> ...