how to delete multiple records with checkboxes in a datagrid?

Question

hello sir,

im trying to delete multiple records with checkboxes in datagrid but im getting an error 

ie

Object reference not set to an instance of an object

 at line 

 dgids = CType(i.FindControl("id"), Label).ToString()

here is my sample code

Dim bxschked As Boolean   

        Dim i As DataGridItem

        Dim dgids As String = ""

        For Each i In dg3.Items

            Dim delchkitm As CheckBox

            delchkitm = CType(i.FindControl("chkdel"), CheckBox)

            If (delchkitm.Checked) Then

                bxschked = True

                dgids = CType(i.Cells(0).FindControl("id"), Label).ToString()

            End If

        Next

plz help me out ,im new to asp.net

thanks in advance

hemant