Highlight container on field focus

Highlight container on field focus

Hi,

I'd like to highlight the field container when the field is focused, just like wufoo does. Sample wufoo form can be previewed here: http://tinyurl.com/6rfebn

Although they provide the javascript publicly, but I want to do it with jQuery. I understand it can be done by adding/removing classes, using something like:

$("fieldname").click(function(){
    $("input.class").removeClass("xshown").addClass("xhidden");
    $(this).addClass("yshown");
});


...but that would create too many functions I guess. I'd like to keep it as short as possible.

Many thanks.