function viewcalendar1() {
  kalendarik = window.open("php_calendar/calendar1.php", "kalendarik" , "location=0, menubar=0, scrollbars=0, status=0, titlebar=0, toolbar=0, directories=0, resizable=1, width=200, height=240, top=50, left=250");
  kalendarik.resizeTo(200, 240);
  kalendarik.moveTo(250, 50);
}

function viewcalendar() {
  kalendarik = window.open("php_calendar/calendar2.php", "kalendarik" , "location=0, menubar=0, scrollbars=0, status=0, titlebar=0, toolbar=0, directories=0, resizable=1, width=200, height=240, top=50, left=250");
  kalendarik.resizeTo(200, 240);
  kalendarik.moveTo(250, 50);
}

function insertdate1(d) {
  window.close();
  window.opener.document.getElementById('start_date').value = d;
}

function insertdate2(d) {
  window.close();
  window.opener.document.getElementById('end_date').value = d;
}