JavaScript HREF

You probably need a button, not a link.

Never use "javascript:" "#" or similar as the value of an href attribute.

The purpose of the href attribute is to specify a URL only. If you wish to run JavaScript on an element click, use a button instead.

Bad

<a href="javascript:;" id="share">Share on Facebook</a>

<script>
    $('#share').on('click', function(e) {
        // do fb share stuff
    });
</script>

Good

<!-- a button created with JavaScript -->
<button id="share">Share on Facebook</button>

<script>
    $('#share').on('click', function(e) {
        // do fb share stuff
    });
</script>

Even better

Use progressive enhancement:

<a href="http://www.facebook.com/share?id=12345" id="share">Share on Facebook</a>

<script>
    $('#share').attr('role', 'button');
    $('#share[role=button]').on('click', function(e) {
        this.preventDefault();
        // do fb share stuff
    })
</script>

The screen reader will announce "Share on Facebook. Button" or fallback to "Share on Facebook. Link" if JavaScript is not ready or available.