Remove Trailing Spaces

I have written a function which works in the same way as the concatenate formula but where required it uses an underscore to make up the length (14 Characters) of the result. I seem however to have hit a minor snag when users input trailing spaces. I thought I could use trim to eliminate them but it doesnt seem to be working

Function HypCon(CorpAcct, Subdiv)

Dim n, i, iLen, iLen2 As Integer
Dim sCorpAcct, sSubdiv As String
Dim iLen3, iLen4 As Integer
iLen = Len(Trim(CorpAcct))
iLen2 = 7
iLen3 = Len(Trim(Subdiv))
iLen4 = 5..............