/**
* Opacity function for jQuery
*
* @name .opacity
* @cat Plugins/Effects
* @author Woody Gilk/woody.gilk@gmail.com
*
* @example $(this).opacity(.2);
*/
jQuery.fn.opacity = function(amount) {
	return this.each(function() {
		var obj = jQuery(this);
		if(amount > 1) amount = 1;
		if(amount < 0) amount = 0;
		if($.browser.msie) {
			amount = (parseFloat(amount) * 100);
//TODO already existing filters need to be appended
			obj.css('filter', 'alpha(opacity='+amount+')');
		} else {
			obj.css('opacity', amount);
			obj.css('-moz-opacity', amount);
		}
	});
}