function keySort(dropdownlist,caseSensitive) {
  // check the keypressBuffer attribute is defined on the dropdownlist 
  var undefined; 
  if (dropdownlist.keypressBuffer == undefined) { 
    dropdownlist.keypressBuffer = ''; 
  } 
  // get the key that was pressed 
  var key = String.fromCharCode(window.event.keyCode); 
  dropdownlist.keypressBuffer += key;
  if (!caseSensitive) {
    // convert buffer to lowercase
    dropdownlist.keypressBuffer = dropdownlist.keypressBuffer.toLowerCase();
  }
  // find if it is the start of any of the options 
  var optionsLength = dropdownlist.options.length; 
  for (var n=0; n < optionsLength; n++) { 
    var optionText = dropdownlist.options[n].text; 
    if (!caseSensitive) {
      optionText = optionText.toLowerCase();
    }
    if (optionText.indexOf(dropdownlist.keypressBuffer,0) == 0) { 
      dropdownlist.selectedIndex = n; 
      return false; // cancel the default behavior since 
                    // we have selected our own value 
    } 
  } 
  // reset initial key to be inline with default behavior 
  dropdownlist.keypressBuffer = key; 
  return true; // give default behavior 
}