function trimString() {
	var s = this;
	while (s.indexOf(" ") == 0)
		s = s.substring(1, s.length);
	while ((s.length != 0) && (s.lastIndexOf(" ") == s.length-1))
		s = s.substring(0, s.length-1);
	return s;
}
String.prototype.trim = trimString;