Protected Sub ItemDB(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.DataGridItemEventArgs)
        If CInt(ViewState("tot")) = 1 Then
            If e.Item.ItemType = ListItemType.Item Or e.Item.ItemType = ListItemType.AlternatingItem Then
                Dim btn As Button = CType(e.Item.Cells(10).FindControl("delBtn"), Button)
                btn.Visible = False
            End If

        End If
    End Sub

this will hide the delete button if the i have one recored in data grid this code works well now when i click the edit button then the delete again show so tell me where should i write the code that will hide the delete button again because its not needed.

thanx in advance 

Here's a small example that might help you:

ASPX 

<asp:datagrid id="dgProducts" runat="server" datasourceid="sdsProducts">
	<columns>
		<asp:templatecolumn>
			<itemtemplate>
				<asp:linkbutton id="btnDelete" runat="server" commandname="Delete" text="Delete"
					visible='<%# CanDelete() %>' />
				</itemtemplate>
		</asp:templatecolumn>
	</columns>
</asp:datagrid>
<asp:sqldatasource id="sdsProducts" runat="server" connectionstring="<%$ ConnectionStrings:NorthwindConnectionString %>"
	selectcommand="SELECT * FROM [Products]">
</asp:sqldatasource>

CODE-BEHIND 

protected bool CanDelete()
{
	// Put any condition you want here simply
	// returning true if you want the button
	// visible or false if not
	return false;
}