function updateDefaultValue(e) {
	var currentTarget, relatedTarget;
	
	if(!e) {
		e=window.event;
	}
	
	currentTarget	= (window.event)? e.srcElement: e.target;
	relatedTarget	= (e.toElement)? e.toElement: e.relatedTarget;
	
	switch(e.type) {
		case 'blur':
			if(currentTarget.value === '') {
				currentTarget.value = currentTarget.defaultValue;
			}
			break;
		case 'focus':
			if(currentTarget.value == currentTarget.defaultValue) {
				currentTarget.value = '';
			}
			break;
	}
}