function validate_nwsltr(ID)
		{
			oError = '';
			if(document.getElementById('naam').value.length < 2)      	oError += "Voer a.u.b. uw naam in.\n";
			if(!isValidEmail(document.getElementById('email').value))   oError += "Voer a.u.b. een correct email-adres in.\n";
			if(oError != '') alert(oError);
			else document.getElementById(ID).submit();
		}
							
		function isValidEmail(email, required) 
		{				
				if (required==undefined) required=true;
				if (email==null) 
				{
					if (required) return false;
					return true;				
				}				
				if (email.length==0) 
				{				
					if (required) return false;
					return true;				
				}				
				if (! allValidChars(email)) return false;
				if (email.indexOf('@') < 1) return false; //  must contain @, and it must not be the first character
				else if (email.lastIndexOf('.') <= email.indexOf('@')) return false;  // last dot must be after the @
				else if (email.indexOf('@') == email.length) return false;  // @ must not be the last character
				else if (email.lastIndexOf('.') == email.length) return false;  // . must not be the last character (werkt niet)
				return true;				
		}						
						
		function allValidChars(email) 
		{		
			var parsed = true;			
			var validchars = 'abcdefghijklmnopqrstuvwxyz0123456789@.-_';			
			for (var i=0; i < email.length; i++) 
			{			
				var letter = email.charAt(i).toLowerCase();				
				if (validchars.indexOf(letter) != -1)				
				continue;				
				parsed = false;				
				break;			
			}			
			return parsed;
		}