function checkDateRange(form)
{
  var startDate = new Date(form.start_year.options[form.start_year.selectedIndex].value,
                           form.start_month.options[form.start_month.selectedIndex].value-1,
                           form.start_day.options[form.start_day.selectedIndex].value-1);
  var endDate = new Date(form.end_year.options[form.end_year.selectedIndex].value,
                           form.end_month.options[form.end_month.selectedIndex].value-1,
                           form.end_day.options[form.end_day.selectedIndex].value-1);
  var rangeM = endDate - startDate;
  if (rangeM > 86400000*7) {
    return confirm("WARNING: Date range could return large data set!  Do you wish to continue?");
  }
  else {
    return true;
  }
}