API functions should be declared private and called by a public function
that includes error trapping. You don't mention which API function(s) you
are using, and errors will vary depending on the function. Therefore, the
error trapping requirements will vary.
i.e.,
Private Declare Function apiGetUserName Lib "advapi32.dll" Alias _
"GetUserNameA" (ByVal lpBuffer As String, nSize As Long) As Long
Function NetUserName() As String
Dim lngLen As Long, lngX As Long
Dim strUserName As String
On Error Resume Next
strUserName = String$(254, 0)
lngLen = 255
lngX = apiGetUserName(strUserName, lngLen)
If ( lngX > 0 ) Then
NetUserName = Left$(strUserName, lngLen - 1)
Else
NetUserName = vbNullString
End If
End Function
Also, some API functions, if used inappropriately, will crash your
system...no error handling will save you. So, you must be careful when
using API functions.
