SIM 900 connect to arduino uno..

Dear,
I am using arduino uno board with SIM 900.I want to send and receive messages from SIM 900.I tried GSM example for message send from arduino program but it is not working..Do you know how to write and execute program

What SIM900 board do you have? Link? Documentation?

What example(s) have you tried? (post the code you tried using CODE TAGS!)

I used a SEEED Studio GPRS/SIM900 board with my UNO.. using by SIM card from my cell phone and an example sketch.. I could send simple text messages to target phone numbers.