Error in Flex file when i import in Flex Builder

[JaxNa]

Hi,

I got some error. when i import flex project in Flex builder…

[COLOR=Red]“Could not resolve <s:Application> to a component implementation. ex1_01_solution/src ex1_01_solution.mxml line 5 1276060610937 3”[/COLOR]

can u tell me plz.

Thanks