JavaScript 获取屏幕宽度的实现方法

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<head> 
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> 
<title>无标题文档</title> 
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<body><html> 
<script> 
function a(){ 
document.write( 
"屏幕分辨率为："+screen.width+"*"+screen.height 
+"<br />"+ 
"屏幕可用大小："+screen.availWidth+"*"+screen.availHeight 
+"<br />"+ 
"网页可见区域宽："+document.body.clientWidth 
+"<br />"+ 
"网页可见区域高："+document.body.clientHeight 
+"<br />"+ 
"网页可见区域宽(包括边线的宽)："+document.body.offsetWidth 
+"<br />"+ 
"网页可见区域高(包括边线的宽)："+document.body.offsetHeight 
+"<br />"+ 
"网页正文全文宽："+document.body.scrollWidth 
+"<br />"+ 
"网页正文全文高："+document.body.scrollHeight 
+"<br />"+ 
"网页被卷去的高："+document.body.scrollTop 
+"<br />"+ 
"网页被卷去的左："+document.body.scrollLeft 
+"<br />"+ 
"网页正文部分上："+window.screenTop 
+"<br />"+ 
"网页正文部分左："+window.screenLeft 
+"<br />"+ 
"屏幕分辨率的高："+window.screen.height 
+"<br />"+ 
"屏幕分辨率的宽："+window.screen.width 
+"<br />"+ 
"屏幕可用工作区高度："+window.screen.availHeight 
+"<br />"+ 
"屏幕可用工作区宽度："+window.screen.availWidth 
); 
} 
</script> 
<body onload="a()" > 
</body> 
</html> 
</body> 
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