function CambiarEstilo(id) 
{

	var elementosMenu = getElementsByClassName(document, "a", "current");
	for (k = 0; k< elementosMenu.length; k++) 
		elementosMenu[k].className = "";
	
	if( id != -1 )
	{
		var identity=document.getElementById(id);
		document.getElementById(id).className="current";
	}
}

function getElementsByClassName(oElm, strTagName, strClassName)
{
    var arrElements = (strTagName == "*" && document.all)? document.all : oElm.getElementsByTagName(strTagName);
    var arrReturnElements = new Array();
    strClassName = strClassName.replace(/\-/g, "\\-");
    var oRegExp = new RegExp("(^|\\s)" + strClassName + "(\\s|$)");
    var oElement;
    for(var i=0; i<arrElements.length; i++){
        oElement = arrElements[i];      
        if(oRegExp.test(oElement.className)){
            arrReturnElements.push(oElement);
        }   
    }
    return (arrReturnElements)
}