The following example shows how you can create a simple, inline custom component in Flex 4 using the Component tag and className property and then instantiating new instances using ActionScript. Full code after the jump. <?xml version="1.0" encoding="utf-8"?> <!-- http://blog.flexexamples.com/2009/11/05/creating-a-custom-component-using-the-component-tag-in-flex-4/ --> <s:Application name="Spark_Component_className_test" xmlns:fx="http://ns.adobe.com/mxml/2009" xmlns:s="library://ns.adobe.com/flex/spark">   [...]