/* CountryChange() is called from the onchange event of a select element.
  * param selectObj - the select object which fired the on change event.
  */
 function sizeColour(selectObj) {
   // get the index of the selected option
   var idx = selectObj.selectedIndex;
   // get the value of the selected option
   var which = selectObj.options[idx].value;
   // use the selected option value to retrieve the list of items from the coutnryLists array
   cList = coloursLists[which];
   // get the country select element via its known id
   var cSelect = document.getElementById("sColour");
   // remove the current options from the country select
   var len=cSelect.options.length;
   while (cSelect.options.length > 0) {
      cSelect.remove(0);
   }
   var newOption;
   // create new options
   for (var i=0; i<cList.length; i++) {
      newOption = document.createElement("option");
      newOption.value = cList[i];  // assumes option string and value are the same
      newOption.text=cList[i];
      // add the new option
      try {
         cSelect.add(newOption);  // this will fail in DOM browsers but is needed for IE
      }
      catch (e) {
         cSelect.appendChild(newOption);
      }
   }
 }