How installing a new library ?

[humi001]

I want to compile a program that contains this header:

#include <Xm/ScrolledW.h>

I have noticed that Knoppix doesn't have the Xm library in /usr/include

How and where can i get this library?
Please help me...

[fingers99]

I think you can just do

apt-get install libmotif-dev

(there are a few dependencies, but apt-get should sort those out)