# Building an app user interface layout

**URL:** https://forum.kirupa.com/t/building-an-app-user-interface-layout/275905
**Category:** Uncategorized
**Created:** [November 19, 2008, 10:46pm UTC](https://forum.kirupa.com/t/building-an-app-user-interface-layout/275905 "2008-11-19T22:46:54Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![Binji](https://avatars.discourse-cdn.com/v4/letter/b/cdc98d/32.png) [@Binji](https://forum.kirupa.com/u/Binji)
#### Post date: [November 19, 2008, 10:46pm UTC](https://forum.kirupa.com/t/building-an-app-user-interface-layout/275905/1 "2008-11-19T22:46:54Z")

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First of all Im new to Flex so please be patient with me 🙂

So im using FlashDevelop and im trying to build an user interface. Im trying to do it using VBox and HBox components but i guess im missing something because everytime i add a component (TextField or Label) to a Box ti reports an error on build (cannot convert flash.text::TextField@ee7c161 to mx.core.IUIComponent.).

What am i missing here? Any other advice?