if you are not tracking labor through the DC modules you could use WO-F to enter the labor for that WO in question then use WO-N to post it. Once that is done you then close the WO off. If you are tracking labor through the DC module then depending on your settings you may have to post the labor through DC-H.  
 
An another note there is some WEB training available on the ISTECH website, for a price of coarse but it maybe to your advantage to check it out.
 
http://www.istechsupport.com/traininglibrary.php
 
well worth it if you are not that familiar with EVO.
 

Actually, labor entered at WO-F posts when saving.  Labor entered at WO-M needs to be posted at WO-N.

WO-F allows you enter the machine
WO-M  has you enter the work center ...  
I am not sure why one ask for the center and the other asks for machine?
 
Also if you are using 100th of an hour you need to use WO-F.
 
I would love to use WO-M but we track the machine and time in 100th.