So I get in my car today to go to work at 7 am to find out that my sunroof is NOT WORKING!!!!

i had it open in the 'tilt' position the night before and wanted to close it today but the bastard wont budge...its makes a sudden "hhmmm" noise like the motor is trying to close it but then it doesnt do anything else....

what could it be? the motor? tracking?

thanks in advance for any help!