Help plzz beginner here

helo ppl>>
it is my first experiment with aasterisk and i m kinda stuk…
i have created simple SIP to SIP call scenario.
my si phones are registerd with the ASTERISK and i can see them by si show peers.
but when i make a call the asterisk prompts .NO APPLICATION DIAL for extension.
i have created the extensions in extension .conf where the context matches context = in sip.conf
plzz… hekl… me what this error relates to>>

There is not much anyone can do to assist you if you don’t post the config files and the dial plan.