The sinner's prayer, or the prayer of salvation, whatever you call it, it is a prayer that anyone interested in going to Heaven should pray. It doesn't matter what you think you've done or not done. Romans 10:9(mouse over the verse to see what it says).
"Lord Jesus, I believe you are the Son of God. Thank you for dying on the cross for my sins. Please forgive my sins and give me the gift of eternal life. I ask you in to my life and heart to be my Lord and Savior. I want to serve you always. Thank you Jesus. Amen."If you prayed the prayer above, congratulations. You're name is now recorded in the Book of life.