function css_obter_regras(indice) {
	var theRules;
	if (!document.styleSheets) return null;
	if (document.styleSheets[indice].cssRules)
		theRules = document.styleSheets[indice].cssRules
	else if (document.styleSheets[indice].rules)
		theRules = document.styleSheets[indice].rules
	else return null;
	return theRules;
}