function str_replace (search, replace, subject, count) {

    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];
}
function explode (delimiter, string, limit) { 
    var emptyArray = { 0: '' };
    
    // third argument is not required
    if ( arguments.length < 2 ||
        typeof arguments[0] == 'undefined' ||
        typeof arguments[1] == 'undefined' ) {
        return null;
    }
 
    if ( delimiter === '' ||
        delimiter === false ||
        delimiter === null ) {
        return false;
    }
 
    if ( typeof delimiter == 'function' ||
        typeof delimiter == 'object' ||
        typeof string == 'function' ||
        typeof string == 'object' ) {
        return emptyArray;
    }
 
    if ( delimiter === true ) {
        delimiter = '1';
    }
    
    if (!limit) {
        return string.toString().split(delimiter.toString());
    } else {
        // support for limit argument
        var splitted = string.toString().split(delimiter.toString());
        var partA = splitted.splice(0, limit - 1);
        var partB = splitted.join(delimiter.toString());
        partA.push(partB);
        return partA;
    }
}