function check_enter(form) {
	if(self.event.keyCode==13) {
		form.submit();
	}
}
function valid_email(email) {
	test=new String(email);
	if(test.indexOf('@', 0)==-1) {
		return false;
	}
	if(test.indexOf('.', 0)==-1) {
		return false;
	} else {
		var ind=test.indexOf('.', 0);
	}
	while(ind!=-1) {
		var indl=ind+1;
		ind=test.indexOf('.', indl);
	}
	if((indl-2)<=test.indexOf('@', 0)) {
		return false;
	}
	return true;
}
function check_textarea(thearea, maxcharacters, maxlines) {

}
function back() {
	history.go(-1);
}
setInterval('knipperen()', 500);
function knipperen() {
	if(document.getElementById('knipper')!=null) {
		if(document.getElementById('knipper').style.color=='#000000') {
			document.getElementById('knipper').style.color='#ffffff';
		} else {
			document.getElementById('knipper').style.color='#000000';
		}
	}
}