add link to text using span html

<script type="text/javascript">

    $('.convertableIdentifier').each(function(i, el) {

        // grab the url and the link text
        var url = $(el).html();

        // create a new node with query by decorating a
        // empty a tag
        var newNode = $('<a></a>').attr('href', url).attr('target', '_blank').html(url);

        // replace the current node with our new node
        $(el).replaceWith(newNode);

    });

</script>

<span>http://www.domain.com/about</span>

<a href="http://www.domain.com/about" target="_blank">http://www.domain.com/about</a>

<script type="text/javascript">
    $(document).ready(function(){
        $('td span').each(function(){
            $(this).html("<a href='" + $(this).html() + "' />" + 
                $(this).html() + "</a>");
        });
    });
</script>

<span id="linkChange">http://domain.com</span>

var href = jQuery('#linkChange').html();
var link = "<a href='"+href+"' target='_blank'>"+href+"</a>";

jQuery('#linkChange').replaceWith(link);