Have a look at here

WaldoSmeets.com gave very nice example to add a calculated column to a datagrad as flex example.

Look at Example

Nice tutorial by Sephiroth regarding AMFPHP, Serializer Class, Datagrid data binding and sending objects to flash from PHP via remoting.

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In Macromedia Flex, you can access data from a web service that is created by a different language, such as .net, Java or ColdFusion. This TechNote provides an example of using a .net web service from http://www.webservicex.com/

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Using an alert pop-up dialog box is a common practice to display a quick and easy dialog box in a Macromedia Flex application. However, you will get a compilation error if you try to use it from a Flex component. This TechNote will explain why and show the proper approach to display the alert box from a component.

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