You can adjust the words file in the initGame() function (line 81). The words need to be separated by a |. Words files can be found can be found here. By default, the images made by Symbol Webdesign will be used. If you want to change the imagesource, adjust the HTML part and also the showHangman() function. They need to be begin with 'hm', the error amount and then the extension (example: hm1.bmp).
Edited by Ezzaral: Snipped url. Keep it on site please.