How hide value in dropdownlist using gridview

This is my code:
Private Sub grdOccupants_RowDataBound(sender As Object, e As GridViewRowEventArgs) Handles grdOccupants.RowDataBound
If e.Row.RowType = DataControlRowType.DataRow Then
Dim ddlRoomNo As DropDownList = DirectCast(e.Row.FindControl("ddlRoomNo"), DropDownList)
Dim upto As Integer = ViewState("MaxOcc")
ddlRoomNo.Items.Insert(0, "---Select Room No---")
Dim index As Integer = 1
For i As Integer = 1 To upto
ddlRoomNo.Items.Insert(index, New ListItem(i.ToString(), i.ToString()))
index += 1
Next
End If
End Sub

Griedview Dropdown Selected value not to show in other row dropdownlistin grid