function numbers(evt)
{
    evt = (evt) ? evt : event;
    var charCode = (evt.charCode) ? evt.charCode : ((evt.keyCode) ? evt.keyCode : 
        ((evt.which) ? evt.which : 0));
    if (charCode > 31 && (charCode < 48 || charCode > 57)) {
        return false;
    }
    return true;
}

// user defined onchange handler
function cal_on_change_dummy(cal, object_code) {
	if (object_code == 'day') {
		alert('Date selected: ' + cal.get_formatted_date());
		cal.show_date();
	}
}


var cal_obj2 = null;

var format = '%d-%m-%Y';

// show calendar
function show_cal(el) {

	if (cal_obj2) return;

var datum_veld = document.getElementById("datum_veld");

	cal_obj2 = new RichCalendar();
	cal_obj2.start_week_day = 2;
	cal_obj2.show_time = false;
	cal_obj2.language = 'en';
	cal_obj2.user_onchange_handler = cal2_on_change;
	cal_obj2.user_onclose_handler = cal2_on_close;
	cal_obj2.user_onautoclose_handler = cal2_on_autoclose;

	cal_obj2.parse_date(datum_veld.value, format);

	cal_obj2.show_at_element(datum_veld, "adj_left-bottom");
	cal_obj2.change_skin('alt');
}

// user defined onchange handler
function cal2_on_change(cal, object_code) {
	if (object_code == 'day') {
		document.getElementById("datum_veld").value = cal.get_formatted_date(format);
		cal.hide();
		cal_obj2 = null;
	}
}

// user defined onclose handler
function cal2_on_close(cal) {
	if (window.confirm('Weet u het zeker?')) {
		cal.hide();
		cal_obj2 = null;
	}
}

// user defined onclose handler (used in pop-up mode - when auto_close is true)
function cal2_on_autoclose(cal) {
	cal_obj2 = null;
}