nav = navigator.appName;
	
	cod = navigator.appVersion;	
	
	if(nav == "Microsoft Internet Explorer"){	
		var valor = cod.substr(22, 1);
		if(valor < 8){	
			document.write("<link rel=\"stylesheet\" type=\"text/css\" href=\"css/estilo_ie7.css\" />");
		} 
	}
	if(nav == "Netscape"){
		if(cod.indexOf("Chrome") != -1){
			document.write("<link rel=\"stylesheet\" type=\"text/css\" href=\"css/estilo_chrome.css\" />");
		}	
	}