hey thanks guys...i figured it out...just to clarify....yes i know hash keys are unique. as jeremy said the reason i wanted to compare each key against all the keys was to check if the current key was a prefix of the others. if it wasnt, i wanted i wanted to chop off the last letter of the string. Then keep repeating this process for said key till it was its shortest possible form. Basically rpeat this method for all the keys. The idea was to get each key into its shortest unique form. hope that clears things up a bit.