function print_r(array, return_val) {
  //  discuss at: http://phpjs.org/functions/print_r/
  // original by: Michael White (http://getsprink.com)
  // improved by: Ben Bryan
  // improved by: Brett Zamir (http://brett-zamir.me)
  // improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
  //    input by: Brett Zamir (http://brett-zamir.me)
  //  depends on: echo
  //   example 1: print_r(1, true);
  //   returns 1: 1

  var output = '',
    pad_char = ' ',
    pad_val = 4,
    d = this.window.document,
    getFuncName = function(fn) {
      var name = (/\W*function\s+([\w\$]+)\s*\(/)
        .exec(fn);
      if (!name) {
        return '(Anonymous)';
      }
      return name[1];
    };
  repeat_char = function(len, pad_char) {
    var str = '';
    for (var i = 0; i < len; i++) {
      str += pad_char;
    }
    return str;
  };
  formatArray = function(obj, cur_depth, pad_val, pad_char) {
    if (cur_depth > 0) {
      cur_depth++;
    }

    var base_pad = repeat_char(pad_val * cur_depth, pad_char);
    var thick_pad = repeat_char(pad_val * (cur_depth + 1), pad_char);
    var str = '';

    if (typeof obj === 'object' && obj !== null && obj.constructor && getFuncName(obj.constructor) !==
      'PHPJS_Resource') {
      str += 'Array\n' + base_pad + '(\n';
      for (var key in obj) {
        if (Object.prototype.toString.call(obj[key]) === '[object Array]') {
          str += thick_pad + '[' + key + '] => ' + formatArray(obj[key], cur_depth + 1, pad_val, pad_char);
        } else {
          str += thick_pad + '[' + key + '] => ' + obj[key] + '\n';
        }
      }
      str += base_pad + ')\n';
    } else if (obj === null || obj === undefined) {
      str = '';
    } else { // for our "resource" class
      str = obj.toString();
    }

    return str;
  };

  output = formatArray(array, 0, pad_val, pad_char);

  if (return_val !== true) {
    if (d.body) {
      this.echo(output);
    } else {
      try {
        d = XULDocument; // We're in XUL, so appending as plain text won't work; trigger an error out of XUL
        this.echo('<pre xmlns="http://www.w3.org/1999/xhtml" style="white-space:pre;">' + output + '</pre>');
      } catch (e) {
        this.echo(output); // Outputting as plain text may work in some plain XML
      }
    }
    return true;
  }
  return output;
}