In google spreadsheet I see in the address bar that my doc url is https://docs.google.com/spreadsheet/ccc?key=0AuQ7FOvczgvFdHVzRXFKLTF1dHM5dk1qR1VzNGFDNGc#gid=0
However, when I write Browser.msgBox(SpreadsheetApp.getActiveSpreadsheet().getUrl()); in the script I get the following url
https://docs.google.com/spreadsheet/ccc?key=tusEqJ-1uts9vMjGUs4aC4g
Why is there a discrepancy? Which one should I be using for my integrations?