When href="something/blah/" I need to add the domain $site/something/blah
When href="/someething/blah" I need to add the domain $site/something/blah
when href="http:// I need to do nothing.
when href="www.blah.com I need to add http://
Updated for more specific situation
Simply showing me code to add http:// when it does not exist will not help as there are to many case situations that don't apply to just http://