Dim cbox As CheckBox
Dim i As Integer
For i = 0 To GridView1.Rows.Count - 1
cbox = CType(GridView1.Rows(i).Cells(0).FindControl("CheckBox1"), CheckBox)
If cbox.Checked = True Then
Button3.Text = GridView1.Rows(i).Cells(2).Text
Else
' cbox.Checked = True
End If
Next i