It's true ... JSL cannot be included at the top of this blog space (howevwer thanks for this free blog system).
Try yourself, include JSL inside head tag and .... WOW, your blog will "disappear".
That's another reason to base libraries or every kind of script on JSL that doesn't modify anything, if present.
JSL is an unobtrusive way to implement JS 1.6, not the unique way to use some personal prototypes.
To add my JSHighLighter, that requires JSL, in this blog I had to include external JS sources at the bottom of the blog model ... come on blogspot, trash your String.replace or encodeURIConponent implementation and use JSL :D
P.S. I don't know what was modified, I saw a redirect to an invalid url created by some blogspot script.