var yourBrowser = navigator.userAgent.toLowerCase();
	var isMac = yourBrowser.indexOf("mac") != -1;
	var msie = yourBrowser.indexOf("msie");
	var ns = yourBrowser.indexOf("nav");
	var macVer = yourBrowser.indexOf("5.0");
	
	if(isMac!=1) {
	  document.write('<link rel="STYLESHEET" type="text/css" href="/imps.css">');
	}
	
	if(isMac==1 && macVer == -1) {
	  document.write('<link rel="STYLESHEET" type="text/css" href="/impsMAC.css">');
	}
	
	if(isMac == 1 && msie == 1 && macVer != -1) {
	    document.write('<link rel="STYLESHEET" type="text/css" href="/imps.css">');
	}