function trim(strText) { 
    while (strText.substring(0,1) == ' ') 
        strText = strText.substring(1, strText.length);
    while (strText.substring(strText.length-1,strText.length) == ' ')
        strText = strText.substring(0, strText.length-1);
   return strText;
}

function is_email_en(p) {
     	var reEmail = /^.+\@.+\..+$/;
	if (!reEmail.test(p)) {
          	alert ("Insert a valid E-mail");
          	return false;
     	}
     	return true;
}

function check_form_en(input_form) {
	if (trim(input_form.surname.value) == "") {
		alert("Insert Surname");
		input_form.surname.focus();
		return false;
	}

	if (trim(input_form.name.value) == "") {
		alert("Insert Name");
		input_form.name.focus();
		return false;
	}

	if (trim(input_form.tel.value) == "") {
		alert("Insert Telephone");
		input_form.tel.focus();
		return false;
	}

	if (!is_email_en(input_form.email.value)) {
		input_form.email.focus();
		return false;
	}
}

function is_email_it(p) {
     	var reEmail = /^.+\@.+\..+$/;
	if (!reEmail.test(p)) {
          	alert ("Inserire un indirizzo e-mail valido");
          	return false;
     	}
     	return true;
}

function check_form_it(input_form) {
	if (trim(input_form.surname.value) == "") {
		alert("Inserisci il cognome");
		input_form.surname.focus();
		return false;
	}

	if (trim(input_form.name.value) == "") {
		alert("Inserisci il nome");
		input_form.name.focus();
		return false;
	}

	if (trim(input_form.tel.value) == "") {
		alert("Inserisci il telefono");
		input_form.tel.focus();
		return false;
	}

	if (!is_email_it(input_form.email.value)) {
		input_form.email.focus();
		return false;
	}
}