im porting android on devkit8000 (on ubuntu 10.10).... during 'make' android source code i got stuck on this error.

Exception in thread "main" java.lang.NoClassDefFoundError: com/android/dx/command/Main

The code of main.java file is alright...I have so many .java files in folders and sub folders on which this 'main' file depends.i have no 'class' files.
when i run command.... javac -classpath . Main.java...it again give errors(cannot find symbol).what should i do first??? –

plz if anyone can help me getting out of this trouble.thx