How to receive the post data from the android using php -

i want simple web service in php , receiving request android app , processing , response device . want receive , respond android

this part of android code

list<namevaluepair> arg = new arraylist<namevaluepair>(); arg.add(new basicnamevaluepair("info", "on")); httprequest.sharedinstance().dohttprequest("http://www.xxxx.com/xxx.php", arg); //jsonobject jsonobj = new jsonobject(httprequest.sharedinstance().responsestring);  string responsestr=httprequest.sharedinstance().responsestring; log.v("response", ""+responsestr); 

when prints simple "hello" in php file , can response in android, not receiving request ,i have printed $_post['info'] in php file , value empty .

how can receive info parameter in php posted android app .

my php code in file http://www.xxxx.com/xxx.php

echo $_post['info']; 

thanks , raj