event problem

public event Handler nameinsert; public delegate void Handler(object Sender); public void check() { ... nameinsert(this); } //authorform_newname is een event that is catched private void authorform_newname(object Sender, cAuthorArgs e) { ... check(); } I receive a System.NullReferenceException: Object reference not set to an instance of an object from the nameinsert(this) Does someone know why???