JavaScript lacks convenient syntax for multiline strings (the equivalent of Python's triple-quotes or Perl's "here blocks"), unless you consider this convenient:

var s = "\
line one\n\
line two\n\
line 'three'\n";

This is something ECMAScript 6 is rumored to support (along with other pink fairies and unicorns), once it gets published and adopted. But in the meantime, intrepid JavaScript programmers are left out in the dark. Unless you really need this to preserve sanity and are willing to resort to unconventional methods.

var MultiString = function(f) {
  return f.toString().split('\n').slice(1, -1).join('\n');
}

var ms = MultiString(function() {/**
line one
line two
line 'three'
**/});

Yes, it's as horrible as it looks. And yes, it's sometimes convenient. Naturally for a couple of 3-line strings I probably wouldn't bother. But when you need to cleanly embed multiple long multi-line strings (templating, anyone?) in your source code, I find this pretty useful.