Question

I have a form with inputs and and div container outside of form with help text for each input.

<form>
    <input id="name" />
    <input id="email" />
    <input id="pass" />
</form>
<div class="help-container">
    <p class="help-name"></p>
    <p class="help-email"></p>
    <p class="help-pass"></p>
</div>

Now the .help-container is initially hidden with { display: none; } as well as each child p.

The jQuery I’m having trouble with is:

$("form").find("input").focus(function(){
    var parent = $(this).attr("id");
    $(this).closest("form").next(".help-container").show();
})

1) This does not work. Why?

$("form").find("input").focus(function(){
    var parent = $(this).attr("id");
    $(this).closest("form").next(".help-container").show();
    $(".help-container").children("p").hide();
    $(".help-container").children("p").find(".help-" + parent).show();
})

2) This does not work. Why?

Answer 1

Here are your issues

$("form").find("input").focus(function(){
    var parent = $(this).attr("id");
    $(this).closest("form").next(".help-container").show(); // you show the container
    $(".help-container").children("p").hide(); // hide all p under it - nothing is shown now
    $(".help-container").children("p").find(".help-" + parent).show(); // you're trying to find elements under p with class .help-xxx
})

You need to change it to this

$("form input").focus(function(){
    var parent = $(this).attr("id");
    $(".help-container").children("p").hide();    // hide all p's
    $(".help-container").children("p.help-" + parent).show(); // show relevant p - since you want the p with the matching class
});​

http://jsfiddle.net/vjUme/