function indirizzoEmailValido(indirizzo) {
	if (window.RegExp) {
    var nonvalido = "(@.*@)|(\\.\\.)|(@\\.)|(\\.@)|(^\\.)";
    var valido = "^.+\\@(\\[?)[a-zA-Z0-9\\-\\.]+\\.([a-zA-Z]{2,4}|[0-9]{1,3})(\\]?)$";
    var regnv = new RegExp(nonvalido);
    var regv = new RegExp(valido);
    if (!regnv.test(indirizzo) && regv.test(indirizzo))
      return true;
    return false;
	}
  else {
    if(indirizzo.indexOf("@") >= 0)
      return true;
    return false;
  	}
}
	
var xmlhttp=false;

function ajax(){
try {
  xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
 } catch (e) {
  try {
   xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
  } catch (E) {
   xmlhttp = false;
  }
 }


if (!xmlhttp && typeof XMLHttpRequest!='undefined') {
	try {
		xmlhttp = new XMLHttpRequest();
	} catch (e) {
		xmlhttp=false;
	}
}
if (!xmlhttp && window.createRequest) {
	try {
		xmlhttp = window.createRequest();
	} catch (e) {
		xmlhttp=false;
	}
}
}

	
	function invio(email){
	ajax();
		
		var url= "include/check_email.php?email=" + email;
		xmlhttp.onreadystatechange=handlestatechange;
		xmlhttp.open("GET",url,false);
		xmlhttp.send(null);
	}
	
	function handlestatechange() {
		if (xmlhttp.readyState==4){
			if (xmlhttp.status==200){
				parseresults();
			}
		}
	}
	
	function parseresults (){
		var responseDiv = document.getElementById("email_check");
		//if (responseDiv.hasChildNodes()){
		//responseDiv.removeChild(responseDiv.childNodes[0]);
		//}
		var email_check=xmlhttp.responseText;
		//alert('response='+response);
		if (email_check!=0){
		responseDiv.value=0;
		}
		else responseDiv.value=1;
	}