Flex3 to Flex4 Conversion

Recently i have been doing some upgrade work converting flex 3 mxmls to flex 4.
Not all components/containers have to modified for this upgrade, and i discovered an easy way to find out if a component needs to be converted.
I don't know if many people know about it,but Here is what i discovered.

In the Flash builder (version 4 is called Flash builder version 3 was called Flex Builder), if you take your mouse over a component and wait for a sec, it shows you if the component needs to be changed or not, as shown in the image below.

Here my flex 3 mxml had a Hbox component,and when i move my mouse over the component i am being told that this component needs to be replaced with "BorderContainer" or "HGroup".





Hope this will be helpful for some who is just starting to convert there flex 3 screens to flex 4 screens.