two jars in java

[u2q2w <u2q2w@unb.ca>]

Hello,
Could you please tell me how to compile my.java with two jars? What is the 
command line? Say, "javac -classpath a1.jar;a2.jar my.java", is it correct in 
windows? What is it in linux?
Thank you so much.
Best regards,
shengli