function abrirCreditos(){
	w_width=300;
	w_height=300;
	pos_left = (screen.availWidth - 12 - 300)/2;
	pos_top = (screen.availHeight - 37 - 300)/2;
	url="credit.php";
	window.open(url,"","toolbar=no, location=no, directories=no, status=no, menubar=no, scrollbars=yes, resizable=no, height=" + w_height + ",width=" + w_width + ",left=" + pos_left + ",top=" + pos_top + "");
}
function abrirLogin(url){
	w_width=300;
	w_height=300;
	pos_left = (screen.availWidth - 12 - 300)/2;
	pos_top = (screen.availHeight - 37 - 300)/2;
	window.open(url,"","toolbar=no, location=no, directories=no, status=no, menubar=no, scrollbars=yes, resizable=no, height=" + w_height + ",width=" + w_width + ",left=" + pos_left + ",top=" + pos_top + "");
}
function abrirPopUp(url, w_width, w_height){
	pos_left = (screen.availWidth - 12 - w_width)/2;
	pos_top = (screen.availHeight - 37 - w_height)/2;
	window.open(url,"","toolbar=no, location=no, directories=no, status=no, menubar=no, scrollbars=yes, resizable=yes, height=" + w_height + ",width=" + w_width + ",left=" + pos_left + ",top=" + pos_top + "");
}


/*****************************************************************************************
	* changecss(nombre selector, elemento, valor)
	NO VALE PARA IE Mac NI Safari porque el selector text lo guardan en un formato diferente */
function changecss(myclass,element,value) {
	if (! document.styleSheets){ return;}
	var CSSRules = (document.all) ? 'rules' : 'cssRules';
	for (var i = 0; i < document.styleSheets.length; i++) {
		for (var j = 0; j < document.styleSheets[i][CSSRules].length; j++) {
			if (document.styleSheets[i][CSSRules][j].selectorText == myclass) {
			document.styleSheets[i][CSSRules][j].style[element] = value;
			}
		}
	}
}