I want to add button with image in TextInput Like in image bellow

Please suggest me the crystal clear way to do so!!
The desired way to do this is to create custom component that extends the Flex TextInput Control. You can create a custom skin based on standard TextInputSkin and place icon in that skin.
[EDIT]
Not exactly what you want. But This may help you..
http://saturnboy.com/2010/07/supertextinput-building-a-custom-component/