方法:
function isMobile() {
  var mobile_flag = false;
  //根据userAgent判断是否是手机
 if((navigator.userAgent.match(/(iPhone|iPod|Android|ios|iOS|iPad|WebOS|Symbian|Windows Phone|Phone)/i))) {
    mobile_flag = true;
  }
  //根据屏幕分辨率判断是否是手机
  var screen_width = window.screen.width;
  var screen_height = window.screen.height; 
  if(screen_width < 500 && screen_height < 800){
    mobile_flag = true;
  }
  return mobile_flag;
}
end.