$(document).ready(function() {
	var he_cont=$('#content_top').height();
	var he_left=$('.left_big_box').height();
	if (he_cont>he_left) {
		var roznica=he_cont-he_left+76;
		t = document.createElement('div');   
        $(t).attr("class","fill").css("height",roznica+"px"); 
        $('.left_big_box').children(':last-child').after(t);
	}

});