function doValidateEmail()
{
	//Ensure that before the validation starts, the hidden field is emptied
	document.forms['frmContactEmail'].txtHiddenContactEmail.value = '';

	//Start error-handling
	var blnErrMsg;
	var errMsg;
	var errMsg_Header;
	var errMsg_Details;
	var isValidEmail;
	
	blnErrMsg =			0;
	errMsg =			'';
	errMsg_Header =		'The following error(s) have occured:-\n';
	errMsg_Details =	'';
	
	//Validate main details within the form
	if(document.forms['frmContactEmail'].txtFirstname.value!='')				{document.forms['frmContactEmail'].txtHiddenContactEmail.value=document.forms['frmContactEmail'].txtHiddenContactEmail.value + '|txtFirstname'};
	if(document.forms['frmContactEmail'].txtSurname.value!='')				{document.forms['frmContactEmail'].txtHiddenContactEmail.value=document.forms['frmContactEmail'].txtHiddenContactEmail.value + '|txtSurname'};
	if(document.forms['frmContactEmail'].txtEmailAddress.value!='')				{document.forms['frmContactEmail'].txtHiddenContactEmail.value=document.forms['frmContactEmail'].txtHiddenContactEmail.value + '|txtEmailAddress'};
	if(document.forms['frmContactEmail'].txtTelephone.value!='')					{document.forms['frmContactEmail'].txtHiddenContactEmail.value=document.forms['frmContactEmail'].txtHiddenContactEmail.value + '|txtTelephone'};
	
	//Validate whether all the mandatory fields have been entered
	if(document.forms['frmContactEmail'].txtHiddenContactEmail.value.indexOf("|txtFirstname")>=0)		{}else{errMsg_Details += '\n- First name is a mandatory value';}
	if(document.forms['frmContactEmail'].txtHiddenContactEmail.value.indexOf("|txtSurname")>=0)			{}else{errMsg_Details += '\n- Surname is a mandatory value';}
	if(document.forms['frmContactEmail'].txtHiddenContactEmail.value.indexOf("|txtEmailAddress")>=0)	{}else{errMsg_Details += '\n- Email Address is a mandatory value';}
	if(document.forms['frmContactEmail'].txtHiddenContactEmail.value.indexOf("|txtTelephone")>=0)		{}else{errMsg_Details += '\n- Contact Telephone is a mandatory value';}
	
	//Validate whether all mandatory values have been entered
	//If they have, the length of the string in the hidden details field will be 53
	if(document.forms['frmContactEmail'].txtHiddenContactEmail.value.length!=53)
	{
		//Not all mandatory values have been entered
		blnErrMsg = 1;
		errMsg += errMsg_Details;
	}	

	//Create entire error string here
	if(blnErrMsg==1)
	{
		errMsg = errMsg_Header + errMsg_Details;
		alert(errMsg);
	}
	else
	{	
		//All values have been supplied, perform a check to validate that the email address is syntactically correct
		isValidEmail = emailCheck(document.forms['frmContactEmail'].txtEmailAddress.value)
		if(isValidEmail)
		{
			//alert('ok to submit');
			
			document.forms['frmContactEmail'].submit();
		}
	}
}

function emailCheck (emailStr) 
{
	var email_errMsg_Header = 'The following error(s) have occured:-\n';
	var emailPat=/^(.+)@(.+)$/
	var specialChars="\\(\\)<>@,;:\\\\\\\"\\.\\[\\]"
	var validChars="\[^\\s" + specialChars + "\]"
	var quotedUser="(\"[^\"]*\")"
	var ipDomainPat=/^\[(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})\]$/
	var atom=validChars + '+'
	var word="(" + atom + "|" + quotedUser + ")"
	var userPat=new RegExp("^" + word + "(\\." + word + ")*$")
	var domainPat=new RegExp("^" + atom + "(\\." + atom +")*$")
	var matchArray=emailStr.match(emailPat)

	if (matchArray==null) 
	{
		alert(email_errMsg_Header + "\nThe email address supplied seems to be invalid. (check @ and .'s)")
		return false
	}
												
	var user=matchArray[1]
	var domain=matchArray[2]

	if (user.match(userPat)==null) 
	{											    
		alert(email_errMsg_Header + '\nThe username in the email address is invalid')
		return false
	}
											
	var IPArray=domain.match(ipDomainPat)
	if (IPArray!=null) 
	{
		for (var i=1;i<=4;i++) 
		{
			if (IPArray[i]>255) 
			{
				alert("The Destination IP Address Is Invalid")
				alert(email_errMsg_Header + '\nThe destination IP address is invalid')
				return false
			}
		}
		return true
	}

	var domainArray=domain.match(domainPat)

	if (domainArray==null) 
	{
		alert(email_errMsg_Header + '\nThe email address supplied includes an invalid domain name')
		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>4) 
	{
		alert(email_errMsg_Header + '\nThe email address supplied does not have a correct suffix (.co.uk, .com...)')
		return false
	}
	if (len<2) 
	{
		alert(email_errMsg_Header + '\nThe email address supplied is missing a hostname')
		return false
	}

	//If we've gotten this far, everything's valid	
	return true;
}