I was in Ams in April this year and had bought a 1hr. tram tkt from the driver. We got off at a place and then boarded another tram again within 45 mts. of taking the first tram. Even so, the machine refused to validate the card. The conductor said that since I did not punch it while exiting the first tram, it was no longer valid. Is this the case with the 24/72/96 hr. passes also. Everytime we exit the tram, do we have to punch them also?