通过js判断访客显示器屏幕分辨率并给出提示

<script>
<!--
fw="1920";fh="1200";
var uw=window.screen.width;
var uh=window.screen.height;
if(fw==uw) {
if(fh==uh){document.write("<span class='green'>完全适合做您的桌面</span>")}
else if(fh<uh){document.write("<span class='red'>不适合做您的桌面</span>")}
else {document.write("<span class='yellow'>裁剪以后适合做您的桌面↘</span>")}
}
else if(fw<uw){document.write("<span class='red'>尺寸略小，不适合做您电脑的桌布</span>")}
else if(fw>uw){
if (fw/fh==uw/uh) {document.write("<span class='green'>适合做您的桌面</span>")}
else {document.write("<span class='yellow'>不完全适合您的分辨率，您可以自己动手裁剪↘</span>")}
}
-->
</script>