function nl2br (str, is_xhtml) {
    // Converts newlines to HTML line breaks
    // version: 909.322
    // discuss at: http://phpjs.org/functions/nl2br
    var breakTag = '';

    breakTag = '<br />';
    if (typeof is_xhtml != 'undefined' && !is_xhtml) {
        breakTag = '<br>';
    }

    return (str + '').replace(/([^>]?)\n/g, '$1'+ breakTag +'\n');
}


function strip_tags (str, allowed_tags) {
    // Strips HTML and PHP tags from a string
    // version: 909.322
    // discuss at: http://phpjs.org/functions/strip_tags

    var key = '', allowed = false;
    var matches = [];
    var allowed_array = [];
    var allowed_tag = '';
    var i = 0;
    var k = '';
    var html = '';

    var replacer = function (search, replace, str) {
        return str.split(search).join(replace);
    };

    // Build allowes tags associative array
    if (allowed_tags) {
        allowed_array = allowed_tags.match(/([a-zA-Z0-9]+)/gi);
    }

    str += '';

    // Match tags
    matches = str.match(/(<\/?[\S][^>]*>)/gi);

    // Go through all HTML tags
    for (key in matches) {
        if (isNaN(key)) {
            // IE7 Hack
            continue;
        }

        // Save HTML tag
        html = matches[key].toString();

        // Is tag not in allowed list? Remove from str!
        allowed = false;

        // Go through all allowed tags
        for (k in allowed_array) {
            // Init
            allowed_tag = allowed_array[k];
            i = -1;

            if (i != 0) { i = html.toLowerCase().indexOf('<'+allowed_tag+'>');}
            if (i != 0) { i = html.toLowerCase().indexOf('<'+allowed_tag+' ');}
            if (i != 0) { i = html.toLowerCase().indexOf('</'+allowed_tag)   ;}

            // Determine
            if (i == 0) {
                allowed = true;
                break;
            }
        }

        if (!allowed) {
            str = replacer(html, "", str); // Custom replace. No regexing
        }
    }

    return str;
}

function trim (str, charlist) {
    // Strips whitespace from the beginning and end of a string  
    // version: 909.322
    // discuss at: http://phpjs.org/functions/trim
    var whitespace, l = 0, i = 0;
    str += '';
    
    if (!charlist) {
        // default list
        whitespace = " \n\r\t\f\x0b\xa0\u2000\u2001\u2002\u2003\u2004\u2005\u2006\u2007\u2008\u2009\u200a\u200b\u2028\u2029\u3000";
    } else {
        // preg_quote custom list
        charlist += '';
        whitespace = charlist.replace(/([\[\]\(\)\.\?\/\*\{\}\+\$\^\:])/g, '$1');
    }
    
    l = str.length;
    for (i = 0; i < l; i++) {
        if (whitespace.indexOf(str.charAt(i)) === -1) {
            str = str.substring(i);
            break;
        }
    }
    
    l = str.length;
    for (i = l - 1; i >= 0; i--) {
        if (whitespace.indexOf(str.charAt(i)) === -1) {
            str = str.substring(0, i + 1);
            break;
        }
    }
    
    return whitespace.indexOf(str.charAt(0)) === -1 ? str : '';
}