this.imagePreview = function(target_items, preid){

	$(target_items).hover(function(e){

		var cargada = false;
		var offset = 10;
		var border_top = $(window).scrollTop(); 
		var ancho_disponible = document.body.offsetHeight-e.pageY;
		var newTop = ancho_disponible+border_top;
		var img = new Image();
		img.src = 'img/prensa/thumbs/'+this.rel;
		var este = this;

		/* $(img).load(function(){ }); */												
					
		var rheight; if (img.width>img.height){ rheight=parseInt(200/(img.width/img.height),10); }else{ rheight=parseInt(200*(img.height/img.width),10); }
			
		var sube = rheight + offset;
		
		if(newTop<rheight){
				$(este).prepend("<span id='"+ preid +"'><img src='"+ img.src +"' width='200' border='0' /></span>");
				$(este).children('span').css({borderRadius:'4px 0px 4px 4px', MozBorderRadius:'4px 0px 4px 4px', WebkitBorderRadius:'4px 0px 4px 4px'});
				$('#'+ preid).css('marginBottom', '-1000px').css('top', '-'+ sube +'px').css({opacity:0.8, padding:'10px 10px 0px 10px', height:rheight, borderRadius:'4px 4px 0 0', MozBorderRadius:'4px 4px 0 0', WebkitBorderRadius:'4px 4px 0 0'});
		}else{
				$(este).append("<span id='"+ preid +"'><img src='"+ img.src +"' width='200' border='0' /></span>");
				$(este).children('span').css({borderRadius:'4px 4px 0px 4px', MozBorderRadius:'4px 4px 0px 4px', WebkitBorderRadius:'4px 4px 0px 4px'});
				$('#'+ preid).css('marginBottom', '-1000px').css({opacity:0.8, padding:'0 10px 10px 10px', height:rheight, borderRadius:'0 0 4px 4px', MozBorderRadius:'0 0 4px 4px', WebkitBorderRadius:'0 0 4px 4px'});
		}
		
		$('#'+ preid).fadeIn(10);
    },
	function(){
		$('#'+ preid).remove();
    });
};

$(document).ready(function(){
	imagePreview('a.preview', 'cont_img');
});