lot of erros in

I have downloadet Flash_ActionScript3.0_samples.zip
And used theone caled "Galleries" but can make it work in my one flash
evry time i export it to swf it showes this:

The class or interface 'URLLoader' could not be loaded.
The class or interface 'Event' could not be loaded.
The class or interface 'XMLList' could not be loaded.
The class or interface 'int' could not be loaded.
The class or interface 'int' could not be loaded.
A type identifier is expected after the ':'.
The class or interface 'int' could not be loaded.
The class or interface 'Loader' could not be loaded.
The class or interface 'Event' could not be loaded.
The class or interface 'Loader' could not be loaded.
The class or interface 'MouseEvent' could not be loaded.
Syntax error.
The class or interface 'MouseEvent' could not be loaded.
Syntax error.
The class or interface 'MouseEvent' could not be loaded.

What can bee rong?? i realy want to know.