/*
 * cssjs
 * written by Christian Heilmann (http://icant.co.uk)
 * eases the dynamic application of CSS classes via DOM
 * parameters: action a, object o and class names c1 and c2 (c2 optional)
 * actions: cambia 		exchanges c1 and c2 in object o
 *			anyade 		adds class c1 to object o
 *			quita 		removes class c1 from object o
 *			verifica 	tests if class c1 is applied to object o (true/false)
 * example:	cssjs('swap',document.getElementById('foo'),'bar','baz');
 */

function cssjs(a,o,c1,c2){
	switch (a){
		case 'cambia':
			o.className=!cssjs('verifica',o,c1)?o.className.replace(c2,c1):o.className.replace(c1,c2);
		break;
		case 'anyade':
			if(!cssjs('verifica',o,c1)){o.className+=o.className?' '+c1:c1;}
		break;
		case 'quita':
			var rep=o.className.match(' '+c1)?' '+c1:c1;
			o.className=o.className.replace(rep,'');
		break;
		case 'verifica':
			return new RegExp('\\b'+c1+'\\b').test(o.className)
		break;
	}
}