Form fields named 'name' or 'id' break the form traversal.

[jakefeasel]

This commit ensures that the property being checked is a string, rather than an object.

See this jsfiddle for demonstration of the problem: http://jsfiddle.net/KJyCq/

And this jsfiddle (identical except using my modified version), showing it working: http://jsfiddle.net/KJyCq/1/