//浏览器窗口大小变化时
$(window).resize(function() {
  	var window_width = $(window).width();//获取浏览器窗口宽度
  	if(window_width>1200){
  		window_width = 1200;
  	}
  	var height = window_width*(800/1280);
  	var ticket_with = $('#buy_ticket').width();
    $('#banner').height(height+'px');
    $('#buy_ticket').height(ticket_with*(393/1200)+'px');
});