UDF Not Recalculating

[tanha]

Hi.
Suppose I have the following UDF, which returns the width of the column, but when the column width change (increase or decrease), the UDF is not able to recalculate the column width...what should I do?

'**************** Returns the column width of the active cell.
Public Function COLUMNWIDTH() 
Call Application.Volatile(True)
      COLUMNWIDTH = ActiveCell.COLUMNWIDTH
End Function
'**************** Returns the column width of the active cell.