Sahih Bukhari Volume 008, Book 074, Hadith Number 268.

Narated By Abu Huraira : A man entered the mosque while Allah's Apostle was sitting in one side of the mosque. The man prayed, came, and greeted the Prophet. Allah's Apostle said to him, "Wa 'Alaikas Salam (returned his greeting). Go back and pray as you have not prayed (properly)." The man returned, repeated his prayer, came back and greeted the Prophet. The Prophet said, "Wa alaika-s-Salam (returned his greeting). Go back and pray again as you have not prayed (properly)." The man said at the second or third time, "O Allah's Apostle! Kindly teach me how to pray". The Prophet said, "When you stand for prayer, perform ablution properly and then face the Qibla and say Takbir (Allahu-Akbar), and then recite what you know from the Qur'an, and then bow with calmness till you feel at ease then rise from bowing, till you stand straight, and then prostrate calmly (and remain in prostration) till you feel at ease, and then raise (your head) and sit with calmness till you feel at ease and then prostrate with calmness (and remain in prostration) till you feel at ease, and then raise (your head) and sit with calmness till you feel at ease in the sitting position, and do likewise in whole of your prayer." And Abu Usama added, "Till you stand straight." (See Hadith No. 759, Vol.1)