function chkForm () {
  if (document.MyRegister.Guest.value == "") {
    alert("Please enter your name.");
    document.MyRegister.Guest.focus();
    return false;
  }
  if (document.MyRegister.EMail.value == "") {
    alert("Please enter your e-mail address.");
    document.MyRegister.EMail.focus();
    return false;
  }
  if (document.MyRegister.EMail.value.indexOf("@") == -1) {
    alert("No valid e-mail address was found. Please enter your e-mail address.");
    document.MyRegister.EMail.focus();
    return false;
  }
  if ((document.MyRegister.arrDate_day.value != "-") &&
     (document.MyRegister.arrDate_mon.value != "-") &&
     (document.MyRegister.arrDate_year.value != "-") &&
     (document.MyRegister.deptDate_day.value != "-") &&
     (document.MyRegister.deptDate_mon.value != "-") &&
     (document.MyRegister.deptDate_year.value != "-")){
    var Arrival = new Date(document.MyRegister.arrDate_year.value, document.MyRegister.arrDate_mon.value-1,
                           document.MyRegister.arrDate_day.value); //january = 0
    var Departure = new Date(document.MyRegister.deptDate_year.value, document.MyRegister.deptDate_mon.value-1,
                           document.MyRegister.deptDate_day.value); //january = 0; 
    if (Arrival >= Departure) {
       alert("Departure date >= arrival date. Please correct your input.");
       return false;
    }
    else {var CurrentDate = new Date();                       
          if (Arrival < CurrentDate) {
          alert("Arrival < current date. Please correct your input.");
          return false;
          } 
    }      
  } 
}