function getCss(aClass) {
 for (var sSheet=0; sSheet < document.styleSheets.length; sSheet++){
  for (var rule=0; rule < (document.styleSheets[sSheet].rules||document.styleSheets[sSheet].cssRules).length; rule++) {
	var currentClass = (document.styleSheets[sSheet].rules||document.styleSheets[sSheet].cssRules)[rule].selectorText.substring(1);
	if (currentClass == aClass) {
	 //alert(currentClass);
	 return (document.styleSheets[sSheet].rules||document.styleSheets[sSheet].cssRules)[rule]
	}
   }
  }
  return null
}

function setCssValue(aClass,element,newvaleur) {
 var currentClass = getCss(aClass);
 if (currentClass!=null){
	eval("currentClass.style." + element + " = newvaleur;");
 }
}

function getCssValue(aClass,element) {
 var currentClass = getCss(aClass);
 if (currentClass!=null){
	return eval("currentClass.style." + element);
 }
 return null;
}