Iterating Dictionaries in a Function

[Thinker]

I could not get this simple code work. I am guessing that there is a
bug
in the Python dictionary iterator.
 
def findx(st):
        d = {'a': 1, 'rty': 4, 'er': 2}
        for item in d.keys(): 
                print item    
                if cmp(item.upper(),st.upper()) == 0:
                        print d[item] 
                        return d[item]
                else: 
                        return st
                         
                         
When I call:             
findx('a')               
it finds the key. But when I call:
findx('er')              
it does not find anything since it does not iterate; it just checks
the first item in the dictionary.

Does anyone see where the bug is?