判断宽度的js

<script language="javascript" type="text/javascript">
/*将获取的值存到变量里*/
width_screen=screen.width;
  height_screen=screen.height;
  availWidth_screen=screen.availWidth;
  availHeight_screen=screen.availHeight;
  colorDepth_screen=screen.colorDepth;
  /*end*/
  /*输出值*/
  document.write("你的屏幕宽为："+width_screen+"<br />你的屏幕高为："+height_screen+"<br />你的屏幕可用宽为："+availWidth_screen+"<br />你的屏幕可用高为："+availHeight_screen+"<br />你的颜色设置所有为数为："+colorDepth_screen);
  /*end*/

</script>

<script type="text/javascript">
document.getElementById("sub_left").style.height=document.getElementById("s_content").scrollHeight+"px";
document.getElementById("sub_right").style.height=document.getElementById("s_content").scrollHeight+"px";
</script>