Step 1 - discover make & model of vehicle
Step 2 - book garage service to repair window
Step 2 - alternatively call out mobile car lock specialist
Step 2 - alternatively buy Haynes manual and follow instructions.
The common failure mode is the window winding gear - if you can hear the motor turning when you press the switch and the glass fails to move it'll be broken winding gear. But you do not say - you give precious few details and make a more sensible answer difficult.
Peccavi
March 2011