var isSafari3 = false; 
if( window.devicePixelRatio && window.getMatchedCSSRules ){ 
	isSafari3 = !!window.getMatchedCSSRules(document.documentElement,''); 
}

if(navigator.userAgent.indexOf("Opera") > -1) {
	document.write('<link rel="stylesheet" href="css/opera.css" type="text/css" />');
}
if(navigator.userAgent.indexOf('Safari') > -1) {
	document.write('<link rel="stylesheet" href="css/safari.css" type="text/css" />');
}