function checkData(w) {

	if (w.full_name && w.full_name.value == "")
	{	alert("Please enter you name.");
		w.full_name.focus();
		return false;
	}
	
	if (w.dob_day && w.dob_day.value == "")
	{	alert("Please enter your date of birth.");
		w.dob_day.focus();
		return false;
	}

	if (w.dob_month && w.dob_month.value == "")
	{	alert("Please enter your date of birth.");
		w.dob_month.focus();
		return false;
	}

	if (w.dob_year && w.dob_year.value == "")
	{	alert("Please enter your date of birth.");
		w.dob_year.focus();
		return false;
	}
	
	if (w.i_am_over_18 && w.i_am_over_18.checked == false)
	{	alert("You must be over 18.");
		w.i_am_over_18.focus();
		return false;
	}
	
	if(w.email1 && !validEmail(w.email1.value, "Email Address"))
	{	w.email1.focus();
		return false;
	}
	
	if (w.enquiry && w.enquiry.value == "")
	{	alert("Please enter your order.");
		w.enquiry.focus();
		return false;
	}
	
	if (w.lastname && !validName(w.lastname.value, "Last Name"))
	{	w.lastname.focus();
		return false;
	}

	if (w.friendname  && !validName(w.friendname.value, "Friends Name"))
	{	w.friendname.focus();
		return false;
	}
	
	if(w.friendemail && !validEmail(w.friendemail.value, "Friends Email Address"))
	{	w.friendemail.focus();
		return false;
	}
	
	if(w.phone1 && !validNums(w.phone1.value, "Phone Number"))
	{	w.phone1.focus();
		return false;
	}
	
	if(w.fax1 && !validNums(w.fax1.value, "Fax Number"))
	{	w.fax1.focus();
		return false;
	}
	
	if(w.email && !validEmail(w.email.value, "Email Address"))
	{	w.email.focus();
		return false;
	}

	if(w.address && !validAddress(w.address.value, "Address"))
	{	w.address.focus();
		return false;
	}
	
	if(w.suburb && !validSuburb(w.suburb.value, "Suburb"))
	{	w.suburb.focus();
		return false;
	}
	
	if(w.city && !validCity(w.city.value, "City"))
	{	w.city.focus();
		return false;
	}

	// required field
	if (w.state.selectedIndex == 0)
	{	alert("Please choose a State.");
		w.state.focus();
		return false;
	}

	// if not empty, validate the contents
	if (w.post && !validpost(w.post.value, "Post Code"))
	{	w.post.focus();
		return false;
	}
	
	if (w.services_requested_concierge && w.services_requested_concierge.checked == false &&
		w.services_requested_cleaning_detailing.checked == false &&
		w.services_requested_boat_management.checked == false &&
		w.services_requested_additional_services.checked == false &&
		w.services_requested_not_listed.checked == false)
	{	alert("Please select the services that you require.");
		w.services_requested_concierge.focus();
		return false;
	}
	
	// required field
	if (w.enquiry && w.enquiry.value == "")
	{	alert("Please enter your enquiry.");
		w.enquiry.focus();
		return false;
	}

	// required field
	if (w.comments && w.comments.value == "")
	{	alert("Please enter your comments.");
		w.comments.focus();
		return false;
	}
	
	return true;
}

function validName(n, t)
{	if (n == "")
	{	alert("Please enter your "+ t +".")
		return false;
	}
	else
	{	var Chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ ";
		for (var i = 0; i < n.length; i++)
		{	if (Chars.indexOf(n.charAt(i)) == -1)
			{	alert ("Please enter a valid "+ t +".")
				return false
			}
		}
	}

	return true;
}

function validNums(n, t)
{	if (n == "")
	{	alert("Please enter a "+ t +".")
		return false;
	}
	else
	{	var Chars = "0123456789";
		for (var i = 0; i < n.length; i++)
		{	if (Chars.indexOf(n.charAt(i)) == -1)
			{	alert ("Please enter only numbers in "+ t +".")
				return false
			}
		}
	}
	
	return true;
}


function validEmail(e, t)
{	
	if (e == "")
	{
		alert("Please enter your "+t);
		return false;
	}
	var emailStr = e;
	var emailPat=/^(.+)@(.+)$/;
	var specialChars="\\(\\)<>@,;:\*\\\\\"\\.\\[\\]";
	var validChars="\[^\\s" + specialChars + "\]";
	var quotedUser="([^\"]*\")";
	var ipDomainPat=/^\[(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})\]$/;
	var atom=validChars + '+';
	var word="(" + atom + "|" + specialChars + ")";
	var userPat=new RegExp("^" + word + "(\\." + word + ")*$");
	var domainPat=new RegExp("^" + atom + "(\\." + atom +")*$");
	var matchArray=emailStr.match(emailPat);
	if (matchArray==null)
	{	alert("Your "+ t +" seems incorrect. Please check @ and .'s!");
		return false;
	}

	var user=matchArray[1];
	var domain=matchArray[2];
	if (user.match(userPat)==null)
	{	alert("Please do not use any symbols (ie. quotes or asterisks) other than @ in your "+ t +".");
		return false;
	}

	var IPArray=domain.match(ipDomainPat);
	if (IPArray!=null)
	{  for (var i=1;i<=4;i++)
		  {	if (IPArray[i]>255)
			{	alert("Destination IP address is invalid!");
				return false;
			}
		}
	}

	var domainArray=domain.match(domainPat)
	if (domainArray==null)
	{	alert("Your "+ t +" domain name doesn't seem to be valid.");
		return false;
	}

	var atomPat=new RegExp(atom,"g");
	var domArr=domain.match(atomPat);
	var len=domArr.length;
	if (domArr[domArr.length-1].length<2 || domArr[domArr.length-1].length>3)
	{	alert("Your "+ t +" must end in a three-letter domain, or two letter country.");
		return false;
	}

	var Chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
	if (domArr[domArr.length-1].length == 2 || domArr[domArr.length-1].length == 3)
	{	for (var i = 0; i < domArr[domArr.length-1].length; i++)
		{	if (Chars.indexOf(domArr[domArr.length-1].charAt(i)) == -1)
			{	alert("The domain name can only contain letters.");
				return false;
			}
		}
	}

	if (len<2 || len>3)
	{	alert("Your "+ t +" is missing a hostname!");
		return false;
	}

	return true;
}

function validCompany(n, t)
{	if (n == "")
	{	alert("Please enter your "+ t +".")
		return false;
	}
	else
	{	var Chars = "1234567890abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ -";
		for (var i = 0; i < n.length; i++)
		{	if (Chars.indexOf(n.charAt(i)) == -1)
			{	alert ("Please enter a valid "+ t +".")
				return false
			}
		}
	}

	return true;
}

function validAddress(n, t)
{	if (n == "")
	{	alert("Please enter your "+ t +".")
		return false;
	}
	else
	{	var Chars = "1234567890abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ -";
		for (var i = 0; i < n.length; i++)
		{	if (Chars.indexOf(n.charAt(i)) == -1)
			{	alert ("Please enter a valid "+ t +".")
				return false
			}
		}
	}

	return true;
}

function validSuburb(n, t)
{	if (n == "")
	{	alert("Please enter your "+ t +".")
		return false;
	}
	else
	{	var Chars = "1234567890abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ -";
		for (var i = 0; i < n.length; i++)
		{	if (Chars.indexOf(n.charAt(i)) == -1)
			{	alert ("Please enter a valid "+ t +".")
				return false
			}
		}
	}

	return true;
}

function validCity(n, t)
{	if (n == "")
	{	alert("Please enter your "+ t +".")
		return false;
	}
	else
	{	var Chars = "1234567890abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ -";
		for (var i = 0; i < n.length; i++)
		{	if (Chars.indexOf(n.charAt(i)) == -1)
			{	alert ("Please enter a valid "+ t +".")
				return false
			}
		}
	}

	return true;
}


function validpost(z, t) {
	if (z == "")
	{	alert("Please fill in your "+ t +".");
		return false; 
	}
	else
	{	// check to see that the value contains at least 4 numbers
		if (z.length < 4)
		{	alert ("Please enter at least 4 numbers into the "+ t +" field.");
			return false;
		}
		// check to see that the value contains either 5 or 10 numbers
		if (z.length > 4 )
		{	alert ("Your post code must only contain 4 digits.");
			return false;
		}
		// check to see that the value contains only numbers
		var nums = "0123456789";
		for (var i = 0; i < z.length; i++)
		{	if (nums.indexOf(z.charAt(i)) == -1)
			{	alert ("Please enter only numbers into the "+ t +" field.");
				return false;
			}
		}
	}
	
	return true;
}