window.onload = inicializar;

function inicializar (){
var combo = document.getElementById("newsletter")

var posX = (window.screen.availWidth)/2 - 305;
	var posY = (window.screen.availHeight)/2 - 355;
		
	function popup(mylink, windowname)
	{
	if (! window.focus)return true;
	var href;
	if (typeof(mylink) == 'string')
	   href=mylink;
	else
	   href=mylink.href;
	window.open(href, windowname, 'scrollbars=no, resizable=0, width=630,height=640, top='+posY+', left='+posX);
	return false;
	}
	
	/*var combo = document.getElementById("newsletter");
	combo.onchange = function(){
		alert("cambio");
	}*/
	
	combo.onchange = cambiaCombo;
	
	function cambiaCombo(){
		var newsElegido = combo.options[combo.selectedIndex].value;
		var ruta = String("pdfs/newsletter/Newsletter_" + newsElegido +".pdf");
		window.open(ruta, 'Newsletters');
	}
}