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"), "");
}


function nl2br (str, is_xhtml) {
    var breakTag = '';
    breakTag = '<br />';
    if (typeof is_xhtml != 'undefined' && !is_xhtml) {
        breakTag = '<br>';
    }
    return (str + '').replace(/([^>]?)\n/g, '$1'+ breakTag +'\n');
}