var date_interval=5;

function dateOffset(date,n) {
  var d=toJSDate(date||"");
  d.setTime(d.getTime()+17280000*n);
  return toCalendarDate(d);
}

function beforeSetDateValue(ref_field, target_field, date) {
  if (date!="") {
    var startDate=document.forms[0]["start_date"];
    var endDate=document.forms[0]["end_date"];

    if (target_field==endDate &&
        checkDate(getDateValue(startDate))==0 &&
        compareDates(dateOffset(getDateValue(startDate), date_interval), date)>0) {
      date=getDateValue(endDate);
      alert("Minimum hire is one day, please select again.");
    }
  }

  return date;
}

function afterSetDateValue(ref_field, target_field, date) {
  if (date!="") {
    var startDate=document.forms[0]["start_date"];
    var endDate=document.forms[0]["end_date"];

    if (target_field==startDate &&
        checkDate(getDateValue(endDate))==0 &&
        compareDates(dateOffset(date, date_interval), getDateValue(endDate))>0) {
      setDateValue(endDate, dateOffset(date, date_interval));
    }
  }
}

function checkForm() {
  var startDate=document.forms[0]["start_date"];
  var endDate=document.forms[0]["end_date"];

  if (checkDate(getDateValue(startDate))!=0) {
    alert("Please select a Start Date.");
  }
  else if (checkDate(getDateValue(endDate))!=0) {
    alert("Please select an End Date.");
  }
  else if (compareDates(dateOffset(getDateValue(startDate), date_interval), getDateValue(endDate))>0) {
    alert("End Date should be at least "+date_interval+" days after Start Date.");
  }
  else {
    alert("Dates are good.");
  }
}

function MM_nbGroup(event, grpName) { //v6.0
  var i,img,nbArr,args=MM_nbGroup.arguments;
  if (event == "init" && args.length > 2) {
    if ((img = MM_findObj(args[2])) != null && !img.MM_init) {
      img.MM_init = true; img.MM_up = args[3]; img.MM_dn = img.src;
      if ((nbArr = document[grpName]) == null) nbArr = document[grpName] = new Array();
      nbArr[nbArr.length] = img;
      for (i=4; i < args.length-1; i+=2) if ((img = MM_findObj(args[i])) != null) {
        if (!img.MM_up) img.MM_up = img.src;
        img.src = img.MM_dn = args[i+1];
        nbArr[nbArr.length] = img;
    } }
  } else if (event == "over") {
    document.MM_nbOver = nbArr = new Array();
    for (i=1; i < args.length-1; i+=3) if ((img = MM_findObj(args[i])) != null) {
      if (!img.MM_up) img.MM_up = img.src;
      img.src = (img.MM_dn && args[i+2]) ? args[i+2] : ((args[i+1])? args[i+1] : img.MM_up);
      nbArr[nbArr.length] = img;
    }
  } else if (event == "out" ) {
    for (i=0; i < document.MM_nbOver.length; i++) {
      img = document.MM_nbOver[i]; img.src = (img.MM_dn) ? img.MM_dn : img.MM_up; }
  } else if (event == "down") {
    nbArr = document[grpName];
    if (nbArr)
      for (i=0; i < nbArr.length; i++) { img=nbArr[i]; img.src = img.MM_up; img.MM_dn = 0; }
    document[grpName] = nbArr = new Array();
    for (i=2; i < args.length-1; i+=2) if ((img = MM_findObj(args[i])) != null) {
      if (!img.MM_up) img.MM_up = img.src;
      img.src = img.MM_dn = (args[i+1])? args[i+1] : img.MM_up;
      nbArr[nbArr.length] = img;
  } }
}