[jQuery] intent of $('selector').title() call

[jQuery] intent of $('selector').title() call


John's got an example of chaining in his book, "Pro JavaScript
Techniques", that isn't working for me. More importantly, I don't
understand what the code is intending to do, so I can make an attempt
to fix it. The code in general is adding a help cursor and a red star
to a field in a form to indicate that the field is required. The chain
looks something like this:
$('input.required')
.prev('label')
.css('cursor','help')
.title(errMsg.required)
.append('<span class="required">*</span>');
I've substituted my own explicit error message for errMsg.required,
but javascript complains that .title( "..." ) is not a function. It's
not in the current API. What is the intent of this call?
Howard