Adding Java Api

Question

hi everyone,
i'm a little java programmer, and i've to make a question, maybe stupid for most of you...
yesterday i've downloaded a java api, that should allow me to treat Excel files, downloadable from here:
http://jexcelapi.sourceforge.net/
After putting into my system, i un compressed it, and tryed to make a simple class where i started to learn how it works, but Textpad said that the package doesn't exsists...
then i thought :" damned environmental variables" and i put a new E.V. named CLASSPATH, with the following data: ".;", because i remembered that this entry would allow me to locate java files into my entire system...
but it's not so...
i used to develop programs, small programs, with other packages like corejava and graphicio, but now they are not visible.
i'm thinking now if could concern with the fact that i've formatted c: a couple of days ago, and something critical changed... but WHAT??
at the end, my question is:
how can i make work a downloaded API, just like the excel one?
thank you everyone, i hope i didn't break any rules!
bye!

Answer 1

thank you very much,
infact i've done something like you told me and the package works...
now i can use
import jxl.*;
but another error occurred.
jxl package creator, said that to read an excel workbook, i could write the following code:
import java.io.File;
import java.util.Date;
import jxl.*;
Workbook workbook = Workbook.getWorkbook(new File("myfile.xls"));
where he omits the try-catch block.
once written, i just compile and everything is right, but when i run it, textpad tells me:
java.lang.NoClassDefFoundError: jxl/Workbook
at 12th row of my code, where i wrote "wb=Workbook.getWorkbook(...);"
how it can be possble?
what's wrong!!
(i'm crying)