function generaPopup(URL, xwidth, xheight) {
        var ywidth = xwidth;
        var yheight = xheight;
        xleft =(getViewportWidth() - ywidth) / 2;
        xtop = (getViewportHeight() - yheight) / 2;
        props = 'toolbar=0,scrollbars=1,location=0,statusbar=0,menubar=0,resizable=0,width='+xwidth+',height='+xheight+
                ',top='+xtop+',left='+xleft;
        popup = window.open(URL, 'popup', props);
}

var ajaxActivo = false;
function boletaElectronica(objDiv){
	var objform = $('formtienda');
	objform.action = $("form_action_boleta").value;
	if(ajaxActivo == false)
	{
		ajaxActivo = true;
		$('cargando').style.display = "block";
		objform.send({method:'post', onComplete : function(e) {
				resp = e.split('_');
				$('cargando').style.display = "none";
				if(resp[0] == 'OK')
					generaPopup(resp[1], 850, 800);
					/*alert(resp[1]);*/
				else
					alert(resp[1]);
				ajaxActivo = false;	
			}
		});
	}	
}