function createRequestObject() {
	var ro;
	var browser = navigator.appName;
	if(browser == "Microsoft Internet Explorer") {
		ro = new ActiveXObject("Microsoft.XMLHTTP");	
	} else {
		ro = new XMLHttpRequest();
		if (ro.overrideMimeType){
			ro.overrideMimeType('txt/xml');
		}
	}
	return ro;
}

var http = createRequestObject();

function enviarMail(){
	var nombre= document.getElementById('nombre').value || '';
	var email= document.getElementById('email').value || '';
	var tlf= document.getElementById('telefono').value || '';
	var texto= document.getElementById('texto').value || '';
	var dpto= document.getElementById('para').value || 0;
	if (texto != ''){
		var ranNum= Math.floor(Math.random()*100000);
		var url_envio = '../enviar_mail.php?id='+dpto+'&rnd='+ranNum;
		http.open('post',url_envio,false);
		http.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
		http.setRequestHeader('Accept-Charset', 'UTF-8');
		http.onreadystatechange = handleEnviarMail;
		http.send('nombre='+nombre+'&email='+email+'&tlf='+tlf+'&msg='+texto);
	} else {
		alert('Fill in the field with your query');
	}
}

function handleEnviarMail(){
	if(http.readyState == 4) {
		var txt = http.responseText;
		if (txt.substr(0,5) == 'ERROR'){
			alert('Your query was not sent.\nPlease try it again later.');
		} else {
			document.getElementById('nombre').value= '';
			document.getElementById('email').value= '';
			document.getElementById('telefono').value= '';
			document.getElementById('texto').value= '';
			alert('Your query was sent');
		}
	}
}