Question

$(function(){
    // the next line works fine
    $('#show-forgetForm').hide();
    $('#forgetForm').click(function() {
        // I can't see the form when I click on the link
        $('#show-forgetForm').show();
        return false;  
    }); 
})

HTML:

<a href="#forgetForm" title="show the form">show</a>
<form id="show-forgetForm">
     [...]
</form>

Answer 1

You need to change

<a href="forgetForm">show</a>

to

<a id="forgetForm" href="#">show</a>

That is because $('#forgetForm') tries to find an element with its id, and not its href, attribute being forgetform