function hideEmailForm(document)
{
	mailform = document.getElementById("email_form");
	mailform.style.display = 'none';
	return false;
}

function showEmailForm(document)
{
	mailform = document.getElementById("email_form");
	mailform.style.display = 'block';
	return false;
}

function Trim(sString)
{
	return sString.replace(/^\s+/g, '').replace(/\s+$/g, '');
}

function validateform(frm, sFields)
{
	// csv list of values to check
	var fieldlist = sFields.split(",");
	for(var element=0; element<fieldlist.length; element++)
	{
		var doc = eval('frm.' + fieldlist[element]);
		doc.value = Trim(doc.value);
		if(doc.value == "")
		{
			if (doc.alt)
				alert(doc.alt); 
			else if (doc.title)
				alert(doc.title);
			else
				alert('You must enter a value for ' + fieldlist[element]); 
			doc.focus();
			return false;
		}
	}
	return true;
}

function validateContact(frm)
{
	var lstRequired = "nameFirst,nameLast,address,postcode,email,comments";
	if (validateform(frm, lstRequired))
	{
		if (frm.yob.value.length == 0 || isNaN(frm.yob.value))
		{
			alert("Please enter a valid year of birth")
			return false;
		}
		else{
			return true;
		}
	}
	else{
		return false;
	}
}