Hello, my names emilly ive had my HTC Desire phone for 2 days and it wont send messages anymore, it did the first day. but now comes up as it wont send message? What could i do to fix this problem ?

There can be many ways to Unlock your phone. As far as i know unlocking by codes is the simple and safe way. I will suggest the website Unlock-Zone.com which is doing good service and they were recommended highly in the cell phone forums.
I used them to unlock my cell phone. contacted them and within 30 mins i had my unlock code and my phone was unlocked.
Hope this helps.