A function for getting the last API error message (from code posted by Stefan Pendl on http://libertybasic.conforums.com/index.cgi).

example usage:
calldll #...._
....
.....
ret as boolean
if ret = 0 then notice "Error...."+ErrorMessageFromAPI$()[[code]]
.............
function ErrorMessageFromAPI$()
   calldll #kernel32, "GetLastError", _
      ErrorCode as ulong
      dwFlags = _FORMAT_MESSAGE_FROM_SYSTEM
      nSize = 1024
      lpBuffer$ = space$(nSize); chr$(0)
      dwMessageID = ErrorCode
 
   calldll #kernel32, "FormatMessageA", _
      dwFlags as ulong, _
      lpSource as ulong, _
      dwMessageID as ulong, _
      dwLanguageID as ulong, _
      lpBuffer$ as ptr, _
      nSize as ulong, _
      Arguments as ulong, _
      result as ulong
 
   ErrorMessageFromAPI$ = "Error ";ErrorCode;": "; left$(lpBuffer$, result)
end function