function file_exists (url) {
    var req = this.window.ActiveXObject ? new ActiveXObject("Microsoft.XMLHTTP") : new XMLHttpRequest();
    if (!req) {throw new Error('XMLHttpRequest not supported');}
    req.open('HEAD', url, false);
    req.send(null);
    if (req.status == 200){
        return true;
    }
    return false;
}
var userAgent = navigator.userAgent.toLowerCase();
jQuery.browser = {
	version: (userAgent.match( /.+(?:rv|it|ra|ie|me)[\/: ]([\d.]+)/ ) || [])[1],
	chrome: /chrome/.test( userAgent ),
	safari: /webkit/.test( userAgent ) && !/chrome/.test( userAgent ),
	opera: /opera/.test( userAgent ),
	msie: /msie/.test( userAgent ) && !/opera/.test( userAgent ),
	mozilla: /mozilla/.test( userAgent ) && !/(compatible|webkit)/.test( userAgent )
};
if ($.browser.chrome) {
	if(file_exists(ROOT_DIR+"css/browsers/chrome.css")){
		document.write("<link rel='stylesheet' type='text/css' href='"+ROOT_DIR+"css/browsers/chrome.css'>");
	}
	}else if ($.browser.msie){
   		if ($.browser.version>=7){
			if(file_exists(ROOT_DIR+"css/browsers/ie7.css")){
	  			document.write("<link rel='stylesheet' type='text/css' href='"+ROOT_DIR+"css/browsers/ie7.css'>");
			}
   		}else{
			if(file_exists(ROOT_DIR+"css/browsers/ie6.css")){
	  			document.write("<link rel='stylesheet' type='text/css' href='"+ROOT_DIR+"css/browsers/ie6.css'>");
			}
   		}
	}else if ($.browser.safari) {
		if(file_exists(ROOT_DIR+"css/browsers/safari.css")){
			document.write("<link rel='stylesheet' type='text/css' href='"+ROOT_DIR+"css/browsers/safari.css'>");
		}
	}else if ($.browser.opera) {
		if(file_exists(ROOT_DIR+"css/browsers/opera.css")){
			document.write("<link rel='stylesheet' type='text/css' href='"+ROOT_DIR+"css/browsers/opera.css'>");
		}
	}else if ($.browser.mozilla) {
		if(file_exists(ROOT_DIR+"css/browsers/firefox.css")){
		    document.write("<link rel='stylesheet' type='text/css' href='"+ROOT_DIR+"css/browsers/firefox.css'>");
		}
	}