postform example of LibWWW - accessing security server

hello 
how do i pass the request header information if i use this example(exe) , to
send the foll. info:
1. server = http:\\server:443\\getCAChain  & set the security on.
2. request headers with 
	UserAgent : MyApp
	Accept : text/*
	Content-type : application/x-www-form-urlencoded
3. request as
op=displayIND&withcertChain=n0&navigatorFormat=no&submit=Submit

currently , my command line parameters are:
postform.exe http://certserver:443/getCAChain op=displayIND withCertChain=no
navigatorFormat=no submit=Submit

but there is nothing in my chunk data....

thanx
meenakshi