If....Then....Else statement in Property Set Definition Help?

[jgardner.79905]

I am defining a tag the has two manual definitions, "Phase" & "Elevation", and am trying to develop a third formula definition that looks something like this:

If [Phase]= Null Then
RESULT = [Elevation]
Else
RESULT = [Phase]|[Elevation]

For some reason I am having trouble getting it to work. I would like the definition to report just the "Elevation" definition value if the "Phase" value is nill. However, if both definitions have values I would like the result to be ("Phase" + "|" + "Elevation"). Can anyone help.

Just as a side note, if it matters, I would like this to work no matter if the user places letters or numbers in the definitions.

Thanks
~Jason

[martin.schmid]

If Len(Trim("[Phase]"))=0 then
RESULT = "[Elevation]"
else
RESULT = "[Phase]|[Elevation]"
end if