function calculateAge(day, month, year)
  { // Calculates the age, given a date
    var thisDate=new Date();
    var thisYear=thisDate.getFullYear();
    var thisMonth=Number(thisDate.getMonth()) + 1;
    var thisDay=Number(thisDate.getDate());
    month=Number(month);
    day=Number(day);
    var age=thisYear-year;
    if (thisMonth>month) {return age;}
    if (thisMonth<month) {return age-1;}
    if (thisDay>=day) {return age;}
    else {return age-1;}
  }


  function checkDate(d,m,y)
  { // Checks for valid date in range 1/1/1900 to 31/12/2099
    if (!isNumeric(d) || !isNumeric(m) || !isNumeric(y)) {return false;}
        if (m<1 || m>12) {return false;}
        if (y<1900 || y>2099) {return false;}
    var daysInMonth=new Array(31,28,31,30,31,30,31,31,30,31,30,31);
        if (y%1000==0 ||(y%4==0 && y%100!=0)) {daysInMonth[1]=29;}
        if (d<1 || d>daysInMonth[m-1]) {return false;}
        return true;
  }


  function checkEmail(email)
  { // this checks for a valid format email address
    var pattern=/^[a-zA-Z0-9]+([.|_|-][a-zA-Z0-9]+)*[@]{1}[a-zA-Z0-9]+([.|_|-][a-zA-Z0-9]+)*[.]{1}[a-zA-Z0-9]{2,3}$/;
    var result=email.match(pattern);
    if (result==null)
      {
       return false;
      }
      else  return true;
  }


  function checkPass(pass)
  { // This checks password is 6-12 chars, starts with a letter and contains
    // only alphanumerics

        if (pass.length<6 || pass.length>12) {return false;}
        var pattern=/^[a-zA-Z][a-zA-Z0-9]{0,11}$/;
    var result=pass.match(pattern);
    if (result==null)
      {
       return false;
      }
      else  return true;
  }

  function checkPhoneNo(phone)
  { // This checks a phone number contains at least 11 digits. It
    // ignores blanks and hyphens
        var p=phone.replace(/ |-/g,""); // Remove blanks or hyphens
    return true;      // Temporary until International nos sorted

    if (p.substring(0,1)=="+")
    {
      p=p.substr(1);
      var pattern="^([0-9]){2}(\([0-9]\))([0-9]{11,})";
      //alert("here");
    }
    else
    { //alert("There");
//      var pattern="^([0-9]{11,})";
    }
    var result= p.match(pattern);
    return result;
//        if (p.length<11 || !isNumeric(p)) {return false;}
//        else {return true;}

  }

  function checkTime(h,m)
  {
    if (!isNumeric(h) || !isNumeric(m)) {return false;}
        if (h<0 || h>23) {return false;}
        if (m<0 || m>59) {return false;}
        return true;
  }

  function checkURL(URL)
  { // this checks for a valid format URL
    // NB this does not check anything beyond the basic address - ie no parameters
    var pattern=/^(http:\/\/)?[a-zA-Z0-9]+([.|_|-][a-zA-Z0-9]+)*[.]{1}[a-zA-Z0-9]{2,3}/;
    var result=URL.match(pattern);
    if (result==null)
      {
       return false;
      }
      else  return true;
  }

  function empty(s)
  {
    if (s=="" || s==null || isblank(s)) {return true;}
        else {return false;}
  }

  function formatDecimal(number)
  { // This takes a number and converts it to a string with 2 decimal places.
    var stringValue=String(number);
    var point=stringValue.search(/\./);
    if (point==-1) {stringValue+=".00";}
    else
    {
      if (point==stringValue.length-1) {stringValue+="00";}
      else
      {
        if (point==stringValue.length-2) {stringValue+="0";}
        else {stringValue=stringValue.substr(0,point+3);}
      }
    }
    return stringValue;
  }

  function generateRandomNo(x, y)
  { // This function generates a random integer between x & y
    var range = y - x + 1;
    return Math.floor(Math.random() * range) + x;
  }

  function getElement(id)
  {
    if (document.getElementById) {var elmt=document.getElementById(id);}
    else
    {
      if (document.all) {var elmt=document.all[id];}
          else
          {
            if (document.layers) {var elmt=document.layers[id];}
            else elmt=false;
          }
    }
    return elmt;
  }

  function isblank (s)
  { // Returns false if field contains any non-blank chars other than new line
    for (var i=0; i<s.length; i++) {
      var c=s.charAt(i);
          if (c!=" " && c!="\n" && c!="") {
          return false;
          }
    }
    return true;
  }


  function isNumeric (number, decPlaces)
  { // This function checks for numerics with a maximum of decPlaces decimal places
    var pattern="/^[0-9]+$/";
    if (decPlaces!='0')
    { // Decimal places allowed
      var dPlaces=2;
      var strPlaces=String(decPlaces);
      var result=strPlaces.match(pattern);
      if (result)  {dPlaces=decPlaces;}
      pattern=eval("/^[0-9]+([.][0-9]{1," + dPlaces + "})?$/");
    }
    var result=number.match(pattern);
    return result;
  }


  function makeTime(f, timeName)
  { // Returns a string containng the time in hh:mm form
    var opt=eval("f." + timeName + "Hour.selectedIndex");
        var hour=eval("f." + timeName + "Hour.options[opt].text");
        opt=eval("f." + timeName + "AmPm.selectedIndex");
        var amPm=eval("f." + timeName + "AmPm.options[opt].text");
        opt=eval("f." + timeName + "Minutes.selectedIndex");
        var minutes=eval("f." + timeName + "Minutes.options[opt].text");
        if (amPm=="pm" && hour!=12) {hour=Number(hour)+12;}
        else
        {
          if (hour<10) {hour="0"+hour;}
        }
        if (minutes<10) {minutes="0" + minutes;}
        return hour+":"+minutes;
  }


  function newWindow(url, w, h)
  { // Opens URL w in a new window positioned top left and ensures it has the focus
    if (!w) {var wide=400;} else {wide=w;}
        if (!h) {var high=450;} else {high=h;}
        var paras="width=" + wide + ",height=" + high + "align=center scrollbars=yes, left=0, top=0, screenx=0, screeny=0, resizable";
    var x=window.open(url, "newWindow", paras);
        x.window.focus();
  }

  function setRelatedSelect(mainSelectID, dependSelectID, clonedOptions, sel2Default)
  {
    var tempOptions = eval(clonedOptions);
    var sel1 = getElement(mainSelectID);
    var sel2 = getElement(dependSelectID);
    if (sel1.options[sel1.selectedIndex].value == 0)  {sel2.disabled = true;} else {sel2.disabled = false;}
    while (sel2.options.length) {sel2.remove(0);}
    // Create regular expression objects for "select" and the value of the selected option of the main select box as class names
    var pattern1 = /( |^)(select)( |$)/;
    var pattern2 = new RegExp("( |^)(" + sel1.options[sel1.selectedIndex].value + ")( |$)");
    // Iterate through all cloned options
    var optCount = 0;
    for (var i = 0; i < tempOptions.length; i++)
    {
      // If the classname of a cloned option either equals "select" or equals the value of the selected option of the main select box
      if (sel1.options[sel1.selectedIndex].value == 0 || tempOptions[i].className.match(pattern2) || tempOptions[i].className=="any")
      {
        // Clone the option from the hidden option pool and append it to the dynamic select box
        sel2.appendChild(tempOptions[i].cloneNode(true));

        if (sel2Default)
        {  // If a default has been provided, ensure the option is still selected
           if (tempOptions[i].value == sel2Default)
           {
             sel2.options[optCount].selected = true;
           }
        }
        optCount++;
      }
    }
    setPrice();
  }

  function validateDate(f, dateName)
  {
        var opt=eval("f." + dateName + "Day.selectedIndex");
        var day=eval("f." + dateName + "Day.options[opt].text");
        opt=eval("f." + dateName + "Month.selectedIndex");
        var month=eval("f." + dateName + "Month.options[opt].value");
        opt=eval("f." + dateName + "Year.selectedIndex");
        var year=eval("f." + dateName + "Year.options[opt].text");
        return checkDate(day, month, year);
  }

  function validateSlashDate(ddmmyy)
  {
    var dateArray=ddmmyy.split("/");
        var d=dateArray[0];
        var m=dateArray[1];
        var y=dateArray[2];
        if (empty(d) || empty(m) || empty(y)) {return false;}
        var valid=checkDate(d, m, y);
        return valid;
  }

  var currentLeft=0;
  function movePics(direction)
  {
    if (imageNames.length<=imagesVisible) {return;}   // All images already displayed
    if (direction=="R" && currentLeft==0) {return;}  // Already at rightmost point
    var maxLeft=imageNames.length-imagesVisible;
    if (direction=="L" && currentLeft==maxLeft) {return;} // Already at leftmost point

    if (direction=="R")
    {
      currentLeft=currentLeft-imagesVisible;
      if (currentLeft<0) {currentLeft=0;}
    }
    else
    {
      currentLeft=currentLeft+imagesVisible;
      if (currentLeft>maxLeft) {currentLeft=maxLeft;}
    }

    for (var i=0; i<imagesVisible; i++)
    {
       var eName="imageNo" + i;
       var e=getElement(eName);
       e.src="photos/" + imageNames[currentLeft+i];
    }
  }