function isEMailAddr(elem) {
    var str = elem.value;
    var re = /^[\w-]+(\.[\w-]+)*@([\w-]+\.)+[a-zA-Z]{2,7}$/;
    if (!str.match(re)) {
        alert("Verify the e-mail address format.");
        elem.focus();
        return false;
    } else {
        return true;
    }
}





function validateForm()
{
 if (document.form1.firstname.value==""){
  alert("Please enter your first name...");
  document.form1.firstname.focus();
  return false;
 }


 if (document.form1.surname.value==""){
  alert("Please enter your surname...");
  document.form1.surname.focus();
  return false;
 }


 if (document.form1.mobilnumber.value==""){
  alert("Please enter your mobil phone number...");
  document.form1.mobilnumber.focus();
  return false;
 }


 if (document.form1.email.value==""){
  alert("Please enter your email...");
  document.form1.email.focus();
  return false;
 }

if(!isEMailAddr(document.form1.email)) return false;



 if (document.form1.orjin_airport.value==""){
  alert("Please enter your departure airport...");
  document.form1.orjin_airport.focus();
  return false;
 }

 if (document.form1.flight_number.value==""){
  alert("Please enter your flight number...");
  document.form1.flight_number.focus();
  return false;
 }

 if (document.form1.airlines.value==""){
  alert("Please enter your airline company...");
  document.form1.airlines.focus();
  return false;
 }

 if (document.form1.destination_airport.value==""){
  alert("Please enter your arriving airport in Turkey...");
  document.form1.destination_airport.focus();
  return false;
 }

 
 if (document.form1.number_of_passenger.value==""){
  alert("Please enter the number of passenger...");
  document.form1.number_of_passenger.focus();
  return false;
 }

 if (document.form1.destination_address.value==""){
  alert("Please enter the destination address ...");
  document.form1.destination_address.focus();
  return false;
 }

 return TRUE;

}