/*
 * ComboSearcher.js
 *
 * Usage:
 *  Just add the following events to your SELECT Tag.
 *  onfocus="initComboSearch();" onkeydown="searchComboBox(this);"
 *
 */


var comboSearchChars;
var KEY_BACKSPACE = 8;

function initComboSearch() {
  comboSearchChars = "";
}

function searchComboBox(theComboBox) {
  //undo the keypress to avoid the default browser behaviour
  window.event.returnValue = false;
  
  var keyCode = window.event.keyCode;
  if (keyCode == KEY_BACKSPACE) {
    comboSearchChars = comboSearchChars.substring(0, comboSearchChars.length-1);
  } else {
    var keyChar = String.fromCharCode(keyCode);
    comboSearchChars += keyChar.toLowerCase();
  }

  for (var i = 0; i < theComboBox.length; i++) {
    var comboValue = theComboBox.options[i].text.substring(0, comboSearchChars.length);
    comboValue = comboValue.toLowerCase();
    if (comboValue == comboSearchChars) {
      theComboBox.options[i].selected = true;
      return;
    }
  }
}