JS script that invokes CSS code based on browser and resolution

<script language= "JavaScript" >
<!--
if (Window.navigator.userAgent.indexOf ("MSIE") >=1)
{
var ie1024= "";
var ie800= "";
var ie1152= "";
var ieother= "";
ScreenWidth (Ie1024,ie800,ie1152,ieother)
}else{
if (Window.navigator.userAgent.indexOf ("Firefox") >=1)
{
file://if the browser is Firefox
var firefox1024= "";
var firefox800= "";
var firefox1152= "";
var firefoxother= "";
ScreenWidth (Firefox1024,firefox800,firefox1152,firefoxother)
}else{
file://if the browser for other
var other1024= "";
var other800= "";
var other1152= "";
var otherother= "";
ScreenWidth (Other1024,other800,other1152,otherother)
}
}
function ScreenWidth (CSS1,CSS2,CSS3,CSS4) {
if ((screen.width = = 1024) && (screen.height = 768)) {
Setactivestylesheet (CSS1);
}else{
if (Screen.width = && (screen.height = 600)) {
Setactivestylesheet (CSS2);
}else{
if ((Screen.width = = 1152) && (screen.height = 864)) {
Setactivestylesheet (CSS3);
}else{
Setactivestylesheet (CSS4);
}}}
}
function Setactivestylesheet (title) {
document.getElementsByTagName ("link") [0].href= "style/" +title;
}
File://-->
</SCRIPT>

Explain:

var IE1024="";
var IE800="";
var IE1152="";
var IEother="";

Quotation marks are filled in separately, when the user uses IE and the resolution is 1024*768,800*600,1152*864 to use the CSS filename.

var Firefox1024="";
var Firefox800="";
var Firefox1152="";
var Firefoxother="";

Quotation marks are filled in separately, when the user uses FF and the resolution is 1024*768,800*600,1152*864 to use the CSS filename.

var Other1024="";
var Other800="";
var Other1152="";
var Otherother="";

Quotation marks are filled in separately, when the user uses another browser and the resolution is 1024*768,800*600,1152*864 to use the CSS filename.

Do not judge the resolution, only the browser

The following code should be prepared E.qiang the proposal. Implementation automatically invokes different CSS based on browser type.

Code:

<SCRIPT LANGUAGE="JavaScript">
<!--
if (window.navigator.userAgent.indexOf("MSIE")>=1)
{
file://如果浏览器为IE
setActiveStyleSheet("default.css");
}else{
if (window.navigator.userAgent.indexOf("Firefox")>=1)
{
file://如果浏览器为Firefox
setActiveStyleSheet("default2.css");
}else{
file://如果浏览器为其他
setActiveStyleSheet("newsky.css");
}
}
　　 function setActiveStyleSheet(title){
document.getElementsByTagName("link")[0].href="style/"+title;
}
file://-->
</SCRIPT>

Explain:

If the browser is IE, call default.css

If the browser is Firefox, call Default2.css

If the browser is otherwise, call Newsky.css

Usage: Put it in front of