flex中弹出窗口设定

import mx.managers.PopUpManger;
import mx.core.UIComponent;

//下面是弹出的代码
private function popup():void {
    PopUpManager.addPopUp(xxForm, this, true);
    PopUpManager.centerPopUp(XXForm);

//设置弹出画面的值
    XXForm.xx.text = "";

//如果想要弹出的画面上没有灰色的title
    UIComponent(XXForm.titleDisplay).parent.visible = false;
    UIComponent(XXForm,titleDisplay).parent.height = 0;
}