/**
 * Strips all leading and ending whitespaces.
 * @returns the trimmed string.
 */
function trim() {
	var str = this.replace(/^\s+/, "");
	var ws = /\s/;
	var i = str.length;
	while (ws.test(str.charAt(--i)));
	return str.slice(0, i + 1);
}

/**
 * Checks whether a string is empty or not.
 * The string is trimmed before checking if the length is 0.
 * @return <code>true</code> if the trimmed string has a length of 0.
 */
function isEmpty() {
	var testString = this.trim();
	return 0 == testString.length;
}

String.prototype.trim = trim;
String.prototype.isEmpty = isEmpty;