After working with some "Mootools" codes and conducted my initial testing in Firefox, I have encountered an error in IE6 and IE7 indicating "Expected Identifier" for some of my codes. Initially I thought that I may have extra comma's in my codes, which is the usual cause of this error message. After drinking few milo, I saw this code "$dom_list.in.funcList.id" and realized that IE have some reserved javascript words, which includes "in". After replacing in with another value, Tadaah! Problem solved. Thank you IE for making a developer's life more difficult.