Make new alias problem!!!!

The problem :
With AppleScript Studio (xcode) it doesn’t create an alias on the desktop.
with AppleScript Editor this little script works.

rara what’s different??

set TheName to "username"
set ThePass to "password"
--========================--
set TheFolder to ":Volumes:users:users:" & TheName
set ThePath to "afp://server.domain.com/users/users/" & TheName
try
	mount volume ThePath as user name TheName with password ThePass
	delay 1
	tell application "Finder" to open folder "Documents" of folder TheFolder
	
on error
	display dialog "Er is iets fout gegaan bij het inloggen, controleer studentnr. en/of wachtwoord." with icon 2 buttons {"OK"} default button 1 giving up after 5
	return
end try
try
	tell application "Finder"
		(make new alias at (path to desktop folder) with properties {name:"Mijn Documenten"} to alias TheFolder)
	end tell
on error
	display dialog "Er is iets fout gegaan bij het aanmaken van een alias" with icon 2 buttons {"OK"} default button 1 giving up after 5
	return
	
end try