CreateGUI enables you to get started right way designing complex user interface systems. To change the attributes of an element with a script, simply declare a variable of that type in the script, and drag your element over. CreateGUI comes with ten types of elements pre-made for you, but you can also make your own custom element types by extending the CGElement class.
See how easy it is to get started: YouTube Video
An Example of Dynamic Elements: Webplayer
The Official Website: CreateGUI.com