function isEmail(str) {
  // are regular expressions supported?
  var supported = 0;
  if (window.RegExp) {
    var tempStr = "a";
    var tempReg = new RegExp(tempStr);
    if (tempReg.test(tempStr)) supported = 1;
  }
  if (!supported) 
    return (str.indexOf(".") > 2) && (str.indexOf("@") > 0);
  var r1 = new RegExp("(@.*@)|(\\.\\.)|(@\\.)|(^\\.)");
  var r2 = new RegExp("^.+\\@(\\[?)[a-zA-Z0-9\\-\\.]+\\.([a-zA-Z]{2,4}|[0-9]{1,3})(\\]?)$");
  return (!r1.test(str) && r2.test(str));
}

var radio_room = '';
function check_booking() {
if (document.booking.name.value == "")
 { alert("Please enter your name.");
   document.booking.name.focus();
   return false;
  }
if (document.booking.address.value == "")
 { alert("Please enter your address.");
   document.booking.address.focus();
   return false;
  }
if (document.booking.phone.value == "")
 { alert("Please enter your phone number.");
   document.booking.phone.focus();
   return false;
  }  
if (!isEmail(document.booking.email.value))
 { alert("Please enter a valid email address.");
   document.booking.email.focus();
   return false;
  }
if (radio_room =="") {
   alert("Please select the room you would like to book.");
	return false;
   }  
if (document.booking.arrival.value == "")
 { alert("Please enter the date you plan to arrive.");
   document.booking.arrival.focus();
   return false;
  }  
if (document.booking.departure.value == "")
 { alert("Please enter the date you plan to depart.");
   document.booking.departure.focus();
   return false;
  }
if (document.booking.time.value == "")
 { alert("Please enter approximate time you plan to arrive.");
   document.booking.time.focus();
   return false;
  }
if (document.booking.adults.value == "")
 { alert("Please enter the number of adults in your party.");
   document.booking.adults.focus();
   return false;
  }
if (document.booking.security_code.value == "")
 { alert("Please enter the security code.");
   document.booking.security_code.focus();
   return false;
  }
}