function eintreten(element) {
	if (element.name == element.value) {
		element.value = '';
	}
}

function verlassen(element) {
	if (trim(element.value) == '') {
		element.value = element.name;
	}
}

function trim(s) {
	while (s.substring(0,1) == ' ') {
		s = s.substring(1,s.length);
	}
	while (s.substring(s.length-1,s.length) == ' ') {
		s = s.substring(0,s.length-1);
	}
	return s;
}