Uhm, faith spelled runescape wrong?
This mission, like many of the other Javascript missions, simply require you to lookup javascript functions. In this case, the "escape/unescape" function. As you can see from the video there tends to be an online version of any language function that involves conversion.
To pass this mission you simply need to input the unescaped version of the given string is the source code which is ilovemoo.
