function getElmById(aID){
	var element = null;
	
	if(document.getElementById) element=document.getElementById(aID);
	else if(document.layers) element=document.layers[aID];
	else if(document.all) element=document.all[aID];
	
	return element; 
}
function abre_url(url,ancho,alto){
	window.open(url,"enlace","toolbar=0,scrollbars=0,location=0,statusbar=0,menubar=0,resizable=0,width="+ancho+",height="+alto);
}