Access 2013 User Defined Function call from on click not working same as 2007

[imagecko]

I have a button on a form. in the on click I am calling a user defined function. If there are no letters it appears like this:
=showsystemdetails(12345)

if there are letters it autodefaults to this:
=showSystemDetails([D05013368])

Here is my code.

Public Function showSystemDetails(ID)
On Error GoTo showSystemDetailsErr

Dim stDocName As String
Dim stLinkCriteria As String
Dim stSysNum As String

stSysNum = "ID"
stDocName = "frmLookup"
stLinkCriteria = "[system #]=" & "'" & stSysNum & "'"
DoCmd.openForm stDocName, , , stLinkCriteria

Exit Function

showSystemDetailsErr:
MsgBox Err.Description

End Function



For some reason it doesn't like the letter and errors out. this DB was originally written when there were not letters in the system # field. There now are and I do not know how to work around this so that the frmLookup opens with the proper data present. Please help. Thank you very much in advance. Also, I am working with Access 2013 now, originally used 2007.

[imagecko]

Hello again, perhaps I did not put enough detail. In the on click property I'm typing =showsystemdetails(1234) Showsystemdetails is the user defined function. the (1234) is the computer ID. This works perfectly when there are only numbers in the computer ID. It walks through the user defined function, opens the form named frmLookup with the details for computer 1234. If the computer ID includes a Letter, such as (D013456)....which is how all of our computers are now ID'd. Brackets are automatically placed around the computer ID [(D013456)] and the code runs but the frmLookup opens blank. I need frmLookup to open populated with computer ID data for what is in the parenthesis. Please help, and I'm grateful in advance for your assistance.