had a similar problem on my 190e car and solved it twice
so check the following-easiest first.
check your main fuse box for the front electric window fuse-if blown replace it or even if not blown-replace with a new one just to be sure.
next option is the to check the individual e/window switch on the centre console-you may have to remove the console and push the switch out from below after first removing the switch wiring.
then swap it with the driver side front window switch which you know for a fact is working-if your passenger front window works after the swap-you have a faulty/dirty window switch-replace or clean the faulty swtch-here in the u.k-they cost about 10 pounds=15 us bucks.
if this fails your next step is to look at the window motor/reglator in the front passenger door as a last resort!
hope your problem is due to options one or two as these a relatively easy fixes.
keep us posted on your progress.