To change the words used, find the code that starts 'var words = new Array()'. Words for the game appear inbetween the brakets in double quotes, with a comma sperating the words.
For exampe to use the words APPLE and PEARS the code would be: var words = new Array("APPLE", "PEARS")
To use the words APPLE, PEARS and STAIRS and the code would be: var words = new Array("APPLE", "PEARS", "STAIRS")
Words should be in uppercase.