function show_dates(mode,form) {
  if (mode == "since_date") {
    var first_date = document.getElementById("first_date");
    first_date.style.visibility = "visible";
    var apply_button = document.getElementById("apply_button");
    if (apply_button) {
	    apply_button.style.visibility = "visible";
    }
  } else {
	  form.submit();
    //var first_date = document.getElementById("first_date");
    //first_date.style.visibility = "hidden";
  }
}