function checktodo(chkbox) 
{ 
	for (var i=0;i < chkbox.form.elements.length;i++) 
	{ 
		var elemento = chkbox.form.elements[i]; 
		if (elemento.type == "checkbox") 
		{ 
			elemento.checked = chkbox.checked 
		} 
	} 
}

var nav4 = window.Event ? true : false;
function acceptNum(evt){
// NOTE: Backspace = 8, Enter = 13, '0' = 48, '9' = 57
var key = nav4 ? evt.which : evt.keyCode;
return (key <= 8 || key <= 13 || (key >= 48 && key <= 57));
}

function acceptLetra(evt){
// NOTE: Backspace = 8, Enter = 13, '0' = 48, '9' = 57
var key = nav4 ? evt.which : evt.keyCode;
return (key <= 8 || key <= 13 || (key >= 65 && key <= 90) || (key >= 97 && key <= 122) || key==32 ||
	    key==225 || key==209 || key==241 || key==233 || key==237 || key==243 || key==250);
}
function checktodo(chkbox) 
{ 
	for (var i=0;i < chkbox.form.elements.length;i++) 
	{ 
		var elemento = chkbox.form.elements[i]; 
		if (elemento.type == "checkbox") 
		{ 
			elemento.checked = chkbox.checked 
		} 
	} 
}

function abrir_ventana(alto,ancho,pagina) 
{	var H = (screen.height - alto) / 2;
    var L = (screen.width - ancho) / 2;
	window.open(pagina,"","toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=yes,top="+H+",left="+L+",resizable=no,width="+ancho+",height="+alto)
}

function recomendar_pagina()
{
	recomendar(
			   document.getElementById('Nremitente').value,
			   document.getElementById('Eremitente').value,				 
			   document.getElementById('Ndestinatario').value,
			   document.getElementById('Edestinatario').value)		
}


function ocultar_form()
{
	document.getElementById('formRegistro').style.display='none';
	document.getElementById('formMsg').style.display='block';
	document.getElementById('Nremitente').value='';
    document.getElementById('Eremitente').value='';			 
 	document.getElementById('Ndestinatario').value='';
	document.getElementById('Edestinatario').value='';
}

function mensajeError(msg)
{	document.getElementById('msgForm').innerHTML=msg }