JavaScript function to trim Strings (detects native browser support)

string-trim.js

var Trim = (function () {
    "use strict";

    var S, both, left, right;

    S = "";

    if (S.trim && !S.hasOwnProperty("trim")) {
        both = function (str) {
            return S.trim.call(str);
        };
        left = function (str) {
            return S.trimLeft.call(str);
        };
        right = function (str) {
            return S.trimRight.call(str);
        };
    } else {
        both = (function () {
            var re, ret;
            re = /^\s+|\s+$/g;
            ret = function (str) {
                str = "" + (str || "");
                return str.replace(re, "");
            };
            return ret;
        }());
        left = (function () {
            var re, ret;
            re = /^\s+/g;
            ret = function (str) {
                str = "" + (str || "");
                return str.replace(re, "");
            };
            return ret;
        }());
        right = (function () {
            var re, ret;
            re = /\s+$/g;
            ret = function (str) {
                str = "" + (str || "");
                return str.replace(re, "");
            };
            return ret;
        }());
    }

    return {
        both: both,
        left: left,
        right: right
    };
}());