newbie question: how to execute Gtk examples?

[Yurong Sun <ysun ece WPI EDU>]

Hello,

Everything seems fine after I installed Gtk1.2.1 and compiled examples
such as helloworld. But when I typed helloworld in xterm, the message I
got is: 

helloworld: command not found.

However, I can execute helloworld quite well in file manager of GNOME.
When I double clicked helloworld, I got a small window and the button of
"hello world!". Could you please tell me the reason why I cannot just type
the exe file to run it instead (if possible) or tell me what's the problem
I may have?

Thank you very much in advance!

Best,

Yurong