compilation problem

Hi, 

When I am compiling the source code in directory ./parent/visad with "make 
compile" command, 
I am getting a bunch of error messages like: 
--------------------------------------------------------------- 
TourWriter.java:26: Class visad.Tuple not found in import. 
import visad.Tuple; 
       ^ 
TourWriter.java:27: Class visad.VisADException not found in import. 
import visad.VisADException; 
       ^ 
TourWriter.java:28: Class visad.UnimplementedException not found in import. 
import visad.UnimplementedException; 
       ^ 
TourWriter.java:29: Class visad.Unit not found in import. 
import visad.Unit; 
       ^ 
TourWriter.java:32: Superclass visad.data.fits.Tourist of class 
visad.data.fits.TourWriter not found. 
        extends Tourist 
                ^ 
25 errors 
---------------------------------------------------------------------- 
Do you have any idea what happened and how can I fix them? I am working on SGI 
IRIX64. 

Thanks! 

Chengwei Feng