function GoTFK() {
if ((document.Form.dnn$ctr2396$ViewEasyLogin$txtUsername.value > 100000) && (document.Form.dnn$ctr2396$ViewEasyLogin$txtUsername.value < 300000)) {

} else {
	alert('Geen correct verenigingsnummer!');
	document.Form.dnn$ctr2396$ViewEasyLogin$txtUsername.value = "";
}
}