function disableEmptyFields( form, doSubmit )
{	
	var allEmpty = true;
	for ( var i=0; i<form.elements.length; i++ )
		if ( ( form.elements[i].type != 'submit' ) && form.elements[i].value )
			allEmpty = false;

	if ( !allEmpty )
	{
		// disable elements without value
		for ( var i=0; i<form.elements.length; i++ )
			if ( !form.elements[i].value )
				form.elements[i].disabled = true;
		// disable submit buttons to exclude them from URL
		for ( var i=0; i<form.childNodes.length; i++ )
			if ( String( form.childNodes[i].id ).substr( 0, 9 ) == 'submitBtn' )
				form.childNodes[i].disabled = true;
	}

	if ( doSubmit && !allEmpty )
		form.submit();

	return( !allEmpty );
}

function checkSubmit( form, requiredFieldArr, doSubmit )
{
	for ( var idx in requiredFieldArr )
	{
		var el = document.getElementById( idx );
		if ( !el.value )
		{
			alert( 'Vul het veld "' + requiredFieldArr[idx] + '" s.v.p. in.' );
			el.focus();
			return( false );
		}
	}
	
	if ( doSubmit == true )
	{
		//var frm = document.getElementById( 'frm' );
		form.submit();
	}

	return( true );
}

function checkOnSubmit( requiredArr, msg )
{
	submitForm = true;	
	for (var i in requiredArr) 
	{
		var el = document.getElementById(i);
		if (el.type == 'checkbox')
		{
			if (!el.checked)
			{
				submitForm = false;
				document.getElementById(requiredArr[i]).style.color = "#FF0000";
			}
			else
				document.getElementById(requiredArr[i]).style.color = "#666666";
		}
		else
		{
			if (!el.value) 
			{
				document.getElementById(requiredArr[i]).style.color = "#FF0000";
				submitForm = false;
			}
			else
				document.getElementById(requiredArr[i]).style.color = '#666666';
		}
		if (i == 'postCode' && el.value.length < 6)
		{
			var	msgOverWrite = 'De postcode die u heeft ingevuld is niet juist';
			document.getElementById(requiredArr[i]).style.color = "#FF0000";
			submitForm = false;
		}
		if (i == 'phoneNo' && el.value.length < 10)
		{
			var	msgOverWrite = 'Het telefoonnummer heeft niet voldoende cijfers';
			document.getElementById(requiredArr[i]).style.color = "#FF0000";
			submitForm = false;
		}
	}	

	if (!submitForm)
	{
		//alert('Niet alle verplichte velden zijn ingevuld. Deze zijn rood gemarkeerd.');
		var message = 'Not all required fields are filled in. These are the red marked ones. Please fill them in.';		
		if(msg)
		message = msg;
		if (msgOverWrite && !msg)
			message = msgOverWrite;
		alert(message);
	}
	return submitForm;	
}