function substr (str, start, len) {
    // Returns part of a string  
    // 
    // version: 909.322
    // discuss at: http://phpjs.org/functions/substr
    // +     original by: Martijn Wieringa
    // +     bugfixed by: T.Wild
    // +      tweaked by: Onno Marsman
    // +      revised by: Theriault
    // +      improved by: Brett Zamir (http://brett-zamir.me)
    // %    note 1: Handles rare Unicode characters if 'unicode.semantics' ini (PHP6) is set to 'on'
    // *       example 1: substr('abcdef', 0, -1);
    // *       returns 1: 'abcde'
    // *       example 2: substr(2, 0, -6);
    // *       returns 2: false
    // *       example 3: ini_set('unicode.semantics',  'on');
    // *       example 3: substr('a\uD801\uDC00', 0, -1);
    // *       returns 3: 'a'
    // *       example 4: ini_set('unicode.semantics',  'on');
    // *       example 4: substr('a\uD801\uDC00', 0, 2);
    // *       returns 4: 'a\uD801\uDC00'
    // *       example 5: ini_set('unicode.semantics',  'on');
    // *       example 5: substr('a\uD801\uDC00', -1, 1);
    // *       returns 5: '\uD801\uDC00'
    // *       example 6: ini_set('unicode.semantics',  'on');
    // *       example 6: substr('a\uD801\uDC00z\uD801\uDC00', -3, 2);
    // *       returns 6: '\uD801\uDC00z'
    // *       example 7: ini_set('unicode.semantics',  'on');
    // *       example 7: substr('a\uD801\uDC00z\uD801\uDC00', -3, -1)
    // *       returns 7: '\uD801\uDC00z'
    // Add: (?) Use unicode.runtime_encoding (e.g., with string wrapped in "binary" or "Binary" class) to
    // allow access of binary (see file_get_contents()) by: charCodeAt(x) & 0xFF (see https://developer.mozilla.org/En/Using_XMLHttpRequest ) or require conversion first?
    var i = 0,
        allBMP = true,
        es = 0,
        el = 0,
        se = 0,
        ret = '';
    str += '';
    var end = str.length;

    // BEGIN REDUNDANT
    this.php_js = this.php_js || {};
    this.php_js.ini = this.php_js.ini || {};
    // END REDUNDANT
    switch ((this.php_js.ini['unicode.semantics'] && this.php_js.ini['unicode.semantics'].local_value.toLowerCase())) {
    case 'on':
        // Full-blown Unicode including non-Basic-Multilingual-Plane characters
        // strlen()
        for (i = 0; i < str.length; i++) {
            if (/[\uD800-\uDBFF]/.test(str.charAt(i)) && /[\uDC00-\uDFFF]/.test(str.charAt(i + 1))) {
                allBMP = false;
                break;
            }
        }

        if (!allBMP) {
            if (start < 0) {
                for (i = end - 1, es = (start += end); i >= es; i--) {
                    if (/[\uDC00-\uDFFF]/.test(str.charAt(i)) && /[\uD800-\uDBFF]/.test(str.charAt(i - 1))) {
                        start--;
                        es--;
                    }
                }
            } else {
                var surrogatePairs = /[\uD800-\uDBFF][\uDC00-\uDFFF]/g;
                while ((surrogatePairs.exec(str)) != null) {
                    var li = surrogatePairs.lastIndex;
                    if (li - 2 < start) {
                        start++;
                    } else {
                        break;
                    }
                }
            }

            if (start >= end || start < 0) {
                return false;
            }
            if (len < 0) {
                for (i = end - 1, el = (end += len); i >= el; i--) {
                    if (/[\uDC00-\uDFFF]/.test(str.charAt(i)) && /[\uD800-\uDBFF]/.test(str.charAt(i - 1))) {
                        end--;
                        el--;
                    }
                }
                if (start > end) {
                    return false;
                }
                return str.slice(start, end);
            } else {
                se = start + len;
                for (i = start; i < se; i++) {
                    ret += str.charAt(i);
                    if (/[\uD800-\uDBFF]/.test(str.charAt(i)) && /[\uDC00-\uDFFF]/.test(str.charAt(i + 1))) {
                        se++; // Go one further, since one of the "characters" is part of a surrogate pair
                    }
                }
                return ret;
            }
            break;
        }
        // Fall-through
    case 'off':
        // assumes there are no non-BMP characters;
        //    if there may be such characters, then it is best to turn it on (critical in true XHTML/XML)
    default:
        if (start < 0) {
            start += end;
        }
        end = typeof len === 'undefined' ? end : (len < 0 ? len + end : len + start);
        // PHP returns false if start does not fall within the string.
        // PHP returns false if the calculated end comes before the calculated start.
        // PHP returns an empty string if start and end are the same.
        // Otherwise, PHP returns the portion of the string from start to end.
        return start >= str.length || start < 0 || start > end ? !1 : str.slice(start, end);
    }
    return undefined; // Please Netbeans
}

function str_replace (search, replace, subject, count) {
    // http://kevin.vanzonneveld.net
    // +   original by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // +   improved by: Gabriel Paderni
    // +   improved by: Philip Peterson
    // +   improved by: Simon Willison (http://simonwillison.net)
    // +    revised by: Jonas Raoni Soares Silva (http://www.jsfromhell.com)
    // +   bugfixed by: Anton Ongson
    // +      input by: Onno Marsman
    // +   improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // +    tweaked by: Onno Marsman
    // +      input by: Brett Zamir (http://brett-zamir.me)
    // +   bugfixed by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // +   input by: Oleg Eremeev
    // +   improved by: Brett Zamir (http://brett-zamir.me)
    // +   bugfixed by: Oleg Eremeev
    // %          note 1: The count parameter must be passed as a string in order
    // %          note 1:  to find a global variable in which the result will be given
    // *     example 1: str_replace(' ', '.', 'Kevin van Zonneveld');
    // *     returns 1: 'Kevin.van.Zonneveld'
    // *     example 2: str_replace(['{name}', 'l'], ['hello', 'm'], '{name}, lars');
    // *     returns 2: 'hemmo, mars'

    var i = 0, j = 0, temp = '', repl = '', sl = 0, fl = 0,
            f = [].concat(search),
            r = [].concat(replace),
            s = subject,
            ra = r instanceof Array, sa = s instanceof Array;
    s = [].concat(s);
    if (count) {
        this.window[count] = 0;
    }

    for (i=0, sl=s.length; i < sl; i++) {
        if (s[i] === '') {
            continue;
        }
        for (j=0, fl=f.length; j < fl; j++) {
            temp = s[i]+'';
            repl = ra ? (r[j] !== undefined ? r[j] : '') : r[0];
            s[i] = (temp).split(f[j]).join(repl);
            if (count && s[i] !== temp) {
                this.window[count] += (temp.length-s[i].length)/f[j].length;}
        }
    }
    return sa ? s : s[0];
}