I spend ~1 hour to answer my question with no avail.  please bare with
me for this dumb question.

How can I let eclipse to show the System.out.println to show its
"console" window?  

What I tried:

Created a hello world program, which has System.out.println("Hora!");
when i run the program, Console window showup with gray title with

HelloWorld [Java Application] C:\Program Files\Java\jre1.6.0_02\bin\javaw.exe (date)

but the main window stays blank.

I modified code to have for(int i=0; i<100; i++) and with the variable
window i can confirm that the value of i keep increasing. but it doesnt
show the message.

I checked that I can read what i typed on the console window through
System.in.  

I also modified Java Project's property, Run/Debug setting, JRE, and
went to set Runtime JRE to be alternate, and Java executable to be java,
instead of javaw, assuming that javaw is eating the stdout somehow.
this didnt change anything.

Could anybody suggest what else went wrong?

Thank you very much in advance.