function ShowDay() {
  var res = document.getElementById("r");
  var dayNames = new Array("Sun","Mon","Tue","Wed","Thu","Fri","Sat");
  var ryear = res.ResYear.selectedIndex;
  if (ryear < 0)
    ryear = 0;
  ryear = res.ResYear.options[ryear].value;
  var rmonth = res.ResMonth.selectedIndex;
  var rdate = res.ResDate.selectedIndex + 1;
  var rday = new Date(ryear,rmonth,rdate).getDay();
  res.dayweek.value = " " + dayNames[rday]
}

function ResvSetDate() {
  var res = document.getElementById("r");
  // set the time to 30 minutes from now
  var nearest = new Date(new Date().getTime() + 30 * 60 * 1000);
  res.ResMonth.selectedIndex = nearest.getMonth();
  res.ResDate.selectedIndex = nearest.getDate() - 1;
  res.ResYear.selectedIndex = nearest.getFullYear() - 2010;

  ShowDay();
}