Trim() Function in Javascript

function trim(str, chars) {
return ltrim(rtrim(str, chars), chars);
}

function ltrim(str, chars) {
chars = chars || "\\s";
return str.replace(new RegExp("^[" + chars + "]+", "g"), "");
}

function rtrim(str, chars) {
chars = chars || "\\s";
return str.replace(new RegExp("[" + chars + "]+$", "g"), "");
}