0.1->0.2: I've forgot some error-checking, now it's implemented, hope, it
	  works!
0.2->0.3: I've forgot an unlocking of the prog (thanks to Udo Weber) and a
          change in the man-page (thank to Alen Salamun). How should I say:
          Is it murphy? My age? My brain? ;)
0.3->0.4: Hm. Why forgot I to do a logout after doing the job? Ok. works. 
	  Some minor-changes to work with glibc2.
0.4->0.5: some better code implemented.
0.5->0.6: removed a ugly bug in the main routine which 
    crashed the program
