Please help
 

will 700 x 38 tires fit on a rim that had a 700 x 50 tire on it?. i made a big mistake and didn't know how much differnce in size the tires was.Till i took the tires out of the box .i dont realy have any extra cash to get new ones since haveing my bike stolen and issues with new bike

What is the size of the rim? See the table on this page:
http://sheldonbrown.com/tire-sizing.html

i must be doing it wrong because it says the factory tire wont fit on the rim the tire that came on the bike from factory. i dont have a tape measyre but from inside rim lip to lip its about the size of a nickel