compilation error : cannot resolve symbol

i hav created 3 classes in 3 different files. am gettin an error durin compilation. wat shud i do???

C:\s\source>javac -d ..\classes devtestdrive.java
devtestdrive.java:5: cannot resolve symbol
symbol : class device
location: class devtestdrive
device d1=new tv();
^
devtestdrive.java:5: cannot resolve symbol
symbol : class tv
location: class devtestdrive
device d1=new tv();
^
devtestdrive.java:6: cannot resolve symbol
symbol : class device
location: class devtestdrive
device d2=new printer();
^
devtestdrive.java:6: cannot resolve symbol
symbol : class printer
location: class devtestdrive
device d2=new printer();
^
devtestdrive.java:7: cannot resolve symbol
symbol : class device
location: class devtestdrive
device d3=new micro();
^
devtestdrive.java:7: cannot resolve symbol
symbol : class micro
location: class devtestdrive
device d3=new micro();
^
devtestdrive.java:9: cannot resolve symbol
symbol : class devicetester
location: class devtestdrive
devicetester d4=new devicetester();
^
devtestdrive.java:9: cannot resolve symbol
symbol : class devicetester
location: class devtestdrive
devicetester d4=new devicetester();
^
8 errors

re: compilation error : cannot resolve symbol

Set your classpath (-cp), output directory (-d) and sourcepath (-sourcepath) on
your javac command line and compile all your .java files at once (*.java).
Type 'javac -help' for details. Don't forget to 'import' the classes in each others'
source files (if they're in a package).

kind regards,

Jos

re: compilation error : cannot resolve symbol

i compiled .java files all at once... but now am gettin an error at run time,

C:\s\source>java devtestdrive
Exception in thread "main" java.lang.NoClassDefFoundError: devtestdrive

re: compilation error : cannot resolve symbol

Now type 'java -help' and read how you can set the classpath variable for the
JVM itself.

kind regards,

Jos