function backgroundIntro(){
  //document.getElementById('main').style.background = "url('img/background_intro.gif')";
  //document.getElementById('main').style.backgroundRepeat = 'repeat-x';
}

function backgroundInterior(){
  //document.getElementById('main').style.background = "url('img/background_interior.gif')";
  //document.getElementById('main').style.backgroundRepeat = 'repeat-x';
}

function isState(sstate) {

  sstates = "wa|or|ca|ak|nv|id|ut|az|hi|mt|wy" +
  "co|nm|nd|sd|ne|ks|ok|tx|mn|ia|mo" +
  "ar|la|wi|il|ms|mi|in|ky|tn|al|fl" +
  "ga|sc|nc|oh|wv|va|pa|ny|vt|me|nh" +
  "ma|ri|ct|nj|de|md|dc";

  if (sstates.indexOf(sstate.toLowerCase() + "|") > -1) {
    return true;
  } else {
    return false;
  }

}

function isdate(dateStr) {

  var datePat = /^(\d{2})(\/|-)(\d{2})(\/|-)(\d{4})$/;
  var matchArray = dateStr.match(datePat); // is the format ok?

  if (matchArray == null) {
    //alert("Please enter date as mm/dd/yyyy.");
    return false;
  }

  month = matchArray[1]; // p@rse date into variables
  day = matchArray[3];
  year = matchArray[5];

  if (month < 1 || month > 12) { // check month range
    //alert("Month must be between 1 and 12.");
    return false;
  }

  if (day < 1 || day > 31) {
    //alert("Day must be between 1 and 31.");
    return false;
  }

  if ((month==4 || month==6 || month==9 || month==11) && day==31) {
    //alert("Month "+month+" doesn`t have 31 days!");
    return false;
  }

  if (month == 2) { // check for february 29th
    var isleap = (year % 4 == 0 && (year % 100 != 0 || year % 400 == 0));
    if (day > 29 || (day==29 && !isleap)) {
      //alert("February " + year + " doesn`t have " + day + " days!");
      return false;
    }
  }
  return true; // date is valid
}