2 classes in 1 file?

programming flash
1

Can I declare 2 classes in the one AS3 file?

I tried this without success

package
{
public class ClassTest
{
private var a:classTest2;
public function ClassTest()
{
a=new ClassTest2();

    }
}

public class ClassTest2
{
    private var a:int;
    public function ClassTest2()
    {
        
        //a=4;
        //trace("asasas");
    }
}

}