/**
* For gallery images
* 
* @author swdalex
* @param a Node this
* @param img_src String preview image url
* @param a_selector String JQuery selector for highslide expander
* @param img_selector String JQuery selector for image
* @param is_background Boolean place image in background or in src
*/
var prev_image = function(a, img_src, a_selector, img_selector, is_background) {
	$(a_selector).attr('href', a.href);
	
	if (is_background) {
		$(img_selector).css('background-image', 'url(' + img_src + ')');
	} else {
		$(img_selector).attr('src', img_src);
	}
	
	return false;
};