Function SerialNumberExists(SerialNumber)
	Set mywin = CWLStart.CurrentModule.Windows.Item(WINDOW_ID)
	Set Grid = mywin.Controls.Item(GRID_ID).Grid
	
	SerialNumberExists = False
	
	If DEBUG_ON = True Then
		AddDebugLine "Checking existence of SerialNumber: " & SerialNumber
		ShowDebugBox "SerialNumberExists"
	End If
	
	For Row = 1 To Grid.LineCount
		CurrentSerialNumber = Grid.GetCellValue(Row, COLUMN_SERIALNUMBER)
		
		If SerialNumber = CurrentSerialNumber Then
			SerialNumberExists = True
			Exit For
		End If
	Next
End Function