First of all, you should have an 'Exit Function' immediately
before your Errfunction label. But more importantly, if you are
trying to call this function from a worksheet cell, it won't work
because you are attempting the change the value of a cell. A
function that is called from a worksheet cell may only return a
value to the calling cell. It may not change any part of the
Excel environment, and that includes changing the value of a
cell.

Try

Public Function returndate(inidate As Date) As Date
Dim calcdate As Double
calcdate = CDbl(inidate + 5)
On Error GoTo Errfunction
returndate = calcdate
Exit Function
Errfunction:
MsgBox Err.Description
MsgBox Err.Number
End Function



--
Cordially,
Chip Pearson
Microsoft MVP - Excel
Pearson Software Consulting, LLC
www.cpearson.com




"Panagiotis Marantos"
wrote in message
...
i am trying to create a simple code (before i make it more
complicated) but i
fall on the first hurdle.

what is wrong with this?

Public Function returndate(inidate As Date) As Date

Dim calcdate As Double

calcdate = CDbl(inidate + 5)
On Error GoTo Errfunction
Application.Worksheets("Dates Lookup").Range("D6").Value =
calcdate

Errfunction:

MsgBox Err.Description
MsgBox Err.Number

End Function