Actionscript Question d'évaluation

on (release)
{
    err_msg.text=''
    if(userName.length > 0 && userPassword.length > 0)
    {
        var loginVars = new LoadVars();
        loginVars.action = 'login';
        loginVars.username = userName.text;
        loginVars.pass = userPassword.text;
        loginVars.sendAndLoad(php_file, loginVars, 'POST');
        loginButton.enabled = false;
        loginVars.onLoad = function() {
      if (!this.error) {
                if (this.user > 0) {
                    err_msg.text='It works. User greater than 0 ' + this.user;
                } else if (this.user == 0) {
                    err_msg.text='User = 0 ' + this.user;
                } else {
                    err_msg.text='Somethings rotten ' + this.user;
                }
            }
            else {
                if(this.error != undefined) {
                    err_msg.text='error, but not undefined';
                } else {
                    err_msg.text='error is undefined';
                    }
            }
            userName.selectable = true;
      userPassword.selectable = true;
      loginButton.enabled = true;
    }

    }
}