function nuevoAjax(){
    var xmlhttp=false;
    try{
        xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
    }catch(e){
        try {
            xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
        }catch(E){
            xmlhttp = false;
        }
    }
    if (!xmlhttp && typeof XMLHttpRequest!='undefined') {
        xmlhttp = new XMLHttpRequest();
    }
    return xmlhttp;
}
function enviarMail(emis, dest, men, subject){
    c = document.getElementById('resultado_mensaje');

    ajax=nuevoAjax();
    c.innerHTML = '<p style="text-align:center;"><img src="images/loader.gif"/></p>';
    ajax.open("POST", "inc/enviar_mail.php",true);
    ajax.onreadystatechange=function() {
        if (ajax.readyState==4) {
    
            c.innerHTML = ajax.responseText
        }
        borrarCampos()
    }
    ajax.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
    ajax.send("destinatario="+dest+"&emisor="+emis+"&mensaje="+men+"&subject" + subject)
}
function borrarCampos(){
    document.enviar_email.emisor.value="";
    document.enviar_email.email_destino.value="";
    document.enviar_email.mensaje.value="";
    document.enviar_email.email_destino.focus();
}