function equalHeight(group) {
    tallest = 0;
    group.each(function() {
        thisHeight = jQuery(this).height();
        if(thisHeight > tallest) {
            tallest = thisHeight;
        }
    });
    group.height(tallest+20);
}

jQuery(window).load( function () {

	if (jQuery('#wrapper').height() < jQuery(window).height())
	{
		jQuery('#sidebar').height(jQuery(window).height()-jQuery('#header').height()-30);
	}
	equalHeight(jQuery('.columns'));
} );