function trigger_error (error_msg, error_type) {
  // http://kevin.vanzonneveld.net
  // +   original by: Brett Zamir (http://brett-zamir.me)
  // %        note 1: Although this function should only allow the E_USER_ types, we'll allow the
  // %        note 1: others here in order to be able to simulate more types (though should not trigger
  // %        note 1: aggregates like E_STRICT or E_ALL).
  // %        note 1: See also our experimental at() function (to mimic the @ error suppressor)
  // -    depends on: echo
  // *     example 1: trigger_error('This will just be a notice');
  // *     returns 1: true

  // Fix: get to work with set_error_handler()'s handler when that is added

  var type = 0,
    i = 0,
    that = this,
    prepend = '',
    append = '';
  if (!error_type) {
    error_type = 'E_USER_NOTICE';
  }
  var ini_on = function (ini) {
    return that.php_js.ini[ini] && that.php_js.ini[ini].local_value && ((that.php_js.ini[ini].local_value.toString && that.php_js.ini[ini].local_value.toString().toLowerCase && (that.php_js.ini[ini].local_value.toString().toLowerCase() === 'on' || that.php_js.ini[ini].local_value.toString().toLowerCase() === 'true')) || parseInt(that.php_js.ini[ini].local_value, 10) === 1);
  };
  var display_errors = function (type) {
    return that.php_js.ini.error_reporting && (type & that.php_js.ini.error_reporting.local_value) && ini_on('display_errors');
  };
  var TYPES = { // Including all types for completeness, but should not trigger aggregates like E_STRICT or E_ALL
    E_ERROR: 1,
    // Fatal run-time errors. These indicate errors that can not be recovered from, such as a memory allocation problem. Execution of the script is halted.
    E_WARNING: 2,
    // Run-time warnings (non-fatal errors). Execution of the script is not halted.
    E_PARSE: 4,
    // Compile-time parse errors. Parse errors should only be generated by the parser.
    E_NOTICE: 8,
    // Run-time notices. Indicate that the script encountered something that could indicate an error, but could also happen in the normal course of running a script.
    E_CORE_ERROR: 16,
    // Fatal errors that occur during PHP's initial startup. This is like an E_ERROR, except it is generated by the core of PHP.
    E_CORE_WARNING: 32,
    // Warnings (non-fatal errors) that occur during PHP's initial startup. This is like an E_WARNING, except it is generated by the core of PHP.
    E_COMPILE_ERROR: 64,
    // Fatal compile-time errors. This is like an E_ERROR, except it is generated by the Zend Scripting Engine.
    E_COMPILE_WARNING: 128,
    // Compile-time warnings (non-fatal errors). This is like an E_WARNING, except it is generated by the Zend Scripting Engine.
    E_USER_ERROR: 256,
    // User-generated error message. This is like an E_ERROR, except it is generated in PHP code by using the PHP function trigger_error().
    E_USER_WARNING: 512,
    // User-generated warning message. This is like an E_WARNING, except it is generated in PHP code by using the PHP function trigger_error().
    E_USER_NOTICE: 1024,
    // User-generated notice message. This is like an E_NOTICE, except it is generated in PHP code by using the PHP function trigger_error().
    E_STRICT: 2048,
    // Enable to have PHP suggest changes to your code which will ensure the best interoperability and forward compatibility of your code.
    E_RECOVERABLE_ERROR: 4096,
    // Catchable fatal error. It indicates that a probably dangerous error occured, but did not leave the Engine in an unstable state. If the error is not caught by a user defined handle (see also set_error_handler()), the application aborts as it was an E_ERROR.
    E_DEPRECATED: 8192,
    // Run-time notices. Enable this to receive warnings about code that will not work in future versions.
    E_USER_DEPRECATED: 16384,
    // User-generated warning message. This is like an E_DEPRECATED, except it is generated in PHP code by using the PHP function trigger_error().
    E_ALL: 30719 // All errors and warnings, as supported, except of level E_STRICT in PHP < 6.     in:32767, // PHP 6, in:30719, // PHP 5.3.x, in:6143, // PHP 5.2.x, previously:2047, //
  };
  if (typeof error_type === 'number') {
    type = error_type;
  } else { // Allow for a single string or an array of string flags
    error_type = [].concat(error_type);
    for (i = 0; i < error_type.length; i++) {
      // Resolve string input to bitwise
      if (TYPES[error_type[i]]) {
        type = type | TYPES[error_type[i]];
      }
    }
  }
  // BEGIN REDUNDANT
  this.php_js = this.php_js || {};
  this.php_js.ini = this.php_js.ini || {};
  // END REDUNDANT
  if (type & TYPES.E_USER_ERROR || type & TYPES.E_ERROR || type & TYPES.E_CORE_ERROR || type & TYPES.E_COMPILE_ERROR || type & TYPES.E_RECOVERABLE_ERROR || type & TYPES.E_PARSE) {
    if (ini_on('track_errors')) {
      this.$php_errormsg = error_msg; // Can assign to this global, as in PHP (see http://php.net/manual/en/reserved.variables.phperrormsg.php )
    }
    if (display_errors(type)) {
      prepend = this.php_js.ini.error_prepend_string ? this.php_js.ini.error_prepend_string : '';
      append = this.php_js.ini.error_append_string ? this.php_js.ini.error_append_string : '';
      this.echo(prepend + 'Error: ' + error_msg + ' ' + append);
    }
    var e = new Error(error_msg); // Might, for Mozilla, allow to somehow pass in a fileName and lineNumber (2nd and 3rd arguments to Error)
    e.type = type;
    this.php_js.last_error = {
      message: e.message,
      file: e.fileName,
      line: e.lineNumber,
      type: e.type
    }; // fileName and lineNumber presently not working (see note just above)
    throw e;
  }

  if (display_errors(type)) {
    switch (type) {
    case TYPES.E_USER_WARNING:
    case TYPES.E_WARNING:
    case TYPES.E_CORE_WARNING:
    case TYPES.E_COMPILE_WARNING:
      this.echo('Warning: ' + error_msg);
      break;
    case TYPES.E_USER_NOTICE:
    case TYPES.E_NOTICE:
      this.echo('Notice: ' + error_msg);
      break;
    case TYPES.E_DEPRECATED:
    case TYPES.E_USER_DEPRECATED:
      this.echo('Deprecated: ' + error_msg);
      break;
    default:
      throw 'Unrecognized error type';
    }
  }

  return true;
}

trigger_error('This will just be a notice');

true