[AccessD] Reference to InstrRev Function

Hi All,

I'm having a problem with a line of code that I use to remove a file path
from a File name in a Field. The code is

Me.ctlImagePath = Right(Me.ctlImagePath, Len(Me.ctlImagePath)-
InstrRev(me.ctlImagePath,"\"))

The Error I'm Getting is Error 5 Invalid Argument,call or Procedure

This is really frustrating as it worked fime a month ago. I can't help but
think I need to reference something for it to work however I have no idea
what to reference.

any help would be great.

Cheers

Dean