Want to disable Combo item

I want to disable a combo item or items in flex, so the user can only view an item, but not able to select it.

http://DisabledComboBox.as
package pk.com.flexpak.controls
{
/**
* DisabledComboBox.as
*/
import mx.controls.ComboBox;
import mx.core.ClassFactory;
import mx.events.FlexEvent;

public class DisabledComboBox extends ComboBox
{
/**
* Constructor.
*/

public function DisabledComboBox()
{
super();
this.dropdownFactory = new ClassFactory(DisabledList);
this.itemRenderer = new ClassFactory(DisabledListItemRenderer);
}

/**
* @private
*/
override public function set dataProvider(value:Object):void
{
super.dataProvider = value;
moveToEnable();
}

private function moveToEnable():void {
var i:int = -1;
for each (var obj:Object in dataProvider) {
i++;
if (this.selectedIndex == -1) {
this.selectedIndex = 0;
}
if (i < this.selectedIndex) {
continue;
}
if (obj != null
&& ((obj is XML && obj.@enabled == 'false')
|| obj.enabled==false || obj.enabled=='false')){
if(i == this.selectedIndex){
this.selectedIndex++;
}
}
}
if (this.selectedIndex > i) {
this.selectedIndex = 0;
}
}

override public function initialize():void
{
this.toolTip = this.text;
if (initialized)
return;
createChildren();
super.initialize();
}

/**
* @private
* Make sure the drop-down width is the same as the rest of the ComboBox
*/
override protected function updateDisplayList(unscaledWidth:Number,
unscaledHeight:Number):void
{
super.updateDisplayList(unscaledWidth, unscaledHeight);
this.toolTip = this.text;
}

private function textInput_valueCommitHandler(event:FlexEvent):void
{
// update _text if textInput.text is changed programatically
super.text = textInput.text;
dispatchEvent(event);
}

private function textInput_enterHandler(event:FlexEvent):void
{
dispatchEvent(event);
dispatchEvent(new FlexEvent(FlexEvent.VALUE_COMMIT));
}
}
}
//------------------------------------------
package pk.com.flexpak.controls
{

import mx.controls.Label;

public class DisabledListItemRenderer extends Label
{
private var _enabled:Boolean = true;

/**
* Constructor.
*/
public function DisabledListItemRenderer()
{
super();
}

/**
* @private
*/
override public function set data(value:Object):void
{
if (value != null && ((value is XML && value.@enabled == 'false')
|| value.enabled==false || value.enabled=='false')){
this._enabled = false;
}else{
this._enabled = true;
}
super.data = value;
}

override protected function updateDisplayList(unscaledWidth:Number,
unscaledHeight:Number):void
{
super.updateDisplayList(unscaledWidth, unscaledHeight);
if (!this._enabled) {
textField.setColor(getStyle("disabledColor"));
}else{
textField.setColor(getStyle("color"));
}
}
}
}
please visit this link for more detail

http://wmcai.blog.163.com/blog/static/4802420088945053961/