function ChangeCalendar() {

    location.href='calendars.aspx?id=' +     document.getElementById('cboYear').options[document.getElementById('cboYear').selectedIndex].value;
}
function AllowImprints() {
    if(document.getElementById('txtQuantity')!=null) {
        if(document.getElementById('txtQuantity').value>=40) {
            document.getElementById('txtImprint').disabled=false;
        } else {
            document.getElementById('txtImprint').disabled=true;
            document.getElementById('txtImprint').value='';
        }
    }
}