Sorting an array based on the .length property. Stuck in challenge.

The challenge goes like this: Sort the 'saying2' array, on about line 19, so that the words are listed in length order. The shortest first. Use the 'length' property on the strings in the sort function.

Code:

var saying1 = ["The", "quick", "brown", "fox", "jumps", "over", "the", "lazy", "dog"];
var saying2 = ["The", "quick", "brown", "fox", "jumped", "over", "the", "lazy", "dog's", "back"];

saying1.reverse();
saying2.sort(function (a, b) {
    return a.length > b.length
    });

I have written the exact same thing in sublime text and tested it on a local index.html file and it gives me the correct output. Why is the challenge not accepting my answer? Im guessing there is another way of doing this that is better, but right now I'm just scratching my head.. Does anyone have a solution to my problem?

Thanks in advance! Edit: How do I post code like a block? I cant seem to do that.. Sorry! :(