Imam appointed Othman Ibn-e Sa'eed Omary as his deputy for a while. He was from his paternal tribe and was the reliable person to him. Imam through him answered the shi'ites questions.
After Othman Ibn-e Sa'eed, his son Mohammad Ibn-e Othman Omary was appointed as Imam's deputy.
When he passed away, Abul Qasim Hossein Ibn-e Ruh Nobakhti was Imam's special deputy, and after him, Ali Ibn_e Mohammad Samary was Imam's deputy.
Some days before Samary's death (Which occurred in 329 AH), Imam informed him that he would die during 6-day- time after which there would be no other chance for the other person to be Imam's next deputy. Besides, It was mentioned that the Major occultation would occur and its period would last until the day on which God would permit it to be ended and Imam would manifest. According to above decree Imam Zaman (May God hasten his glad advent)'s occultation is divided into two parts:
1. The Minor Occultation, which started from 260 A.H and ended in 329 A.H and it lasted about seventy years.
2. The Major Occultation, which started from 329 A.H and will last as long as God desires.
One of the human's psychological whishes and desires is hoping to have a brighter future filled with the happiness and success. To hope for a brighter and better future is not enough either. It has been created on the basis of a special aim and motivation and it is not exclusively restricted to the special nation or a tribe and it is a universal issue for which the people all around the world wish and seek. As a psychological principle, this matter exists among all the men and nations and can not be denied.
The Islam religion has organized human's innate instincts and it guides them to the special path so that they can go through the Divine perfection and will be immune from any deviation. Therefore; waiting and hoping for the better future is a constant reason for one's perfection and it has been always advised by Islam. Islam religion advises all of the Muslims to follow the righteous guidance because the happiness and prosperity of mankind is only possible under the shadow of the Islamic government.
source : www.sibtayn.com