classpath newbie question

[silentx]

i have been learning java for quiet some time, but i just got to using packages and a problem with my classpath arose, i cant seem to set my classpath permenantly and i have been trying for quite some time, basically what i need to know is why my java.exe cant locate the classpath unless i type set CLASSPATH=. everytime i open dos, or if i type -cp . everytime i want to run my app, i thought the bin dir of jsdk was the defualt place for it to look....thank you!

EDIT***

1. I have a class file in the bin directory, but i have to use "java -cp . myClass" for it to work.

2. I have a class file in C:\j2sdk1.4.2_03\bin\folder
and I have tried everything from:
java -cp .;C:\j2sdk1.4.2_03\bin\folder myClass
to setting the enviroment variable like:
set CLASSPATH=C:\j2sdk1.4.2_03\bin\folder
and no go  

Please lol, I know Im a newb.

[silentx]

ok, fixed the problem, I reread a tutorial on setting the ENV CP variable (prolly shuda done that b4 huh hehe), and to run a package i type : java foldername.myClass