cannot find symbol error

Can any one help me

I have problem in calling Port.java from Msg.java

The all four files are in smspack

I am getting same type error in all four files

The error message is as follows:

Msg.java:192: cannot find symbol

symbol : variable Port

location: class smspack.Msg

s = Port.sendAT ("AT+CSQ");

^

Msg.java:195: cannot find symbol

symbol : variable SMS

location: class smspack.Msg

SMS.showText("Error: getSignalQuality failed: " + e);

^

Msg.java:226: cannot find symbol

symbol : variable Port

location: class smspack.Msg

s = Port.sendAT ("AT+CBC");

[665 byte] By [Raj_Amita] at [2007-10-3 0:54:36]