remote connection with winbox

hi guys
last time i was here i found that i bought a pirated copy of Mikrotik OS but now i have the licensed one. the problem is i want to connect to my MikroTik when i am at work but my isp gives me a dynamic ip address only i found it using no-ip.com but when i try to connect with ip given to me i can not. why???
i am new for such things

Have you configured it to control remote access? Post the contents of “/ip services” and “/ip firewall filter”.

deal with me as if i do not know anything

Do you have a global IP address? Do you have any firewall filters in place?

Read the Manual:
http://wiki.mikrotik.com/wiki/Category:Manual

Both have topics on the wiki you can read up on:

http://wiki.mikrotik.com/wiki/IP/Services
http://wiki.mikrotik.com/wiki/Firewall_filter