I work in bread factory to help salesman .My duty is to go to factory load breads,cakes,biscuits in a bus of only one salesman and then to go with him in market to sale those products . Salesman, with whom i am appointed by factory, is my Uncle . I just go to factory and load products in a bus and then i come back home . My uncle has allowed me to do so . My uncle goes alone to market and sale products . My question is am i allowed to take salary ? because factory members dont know that i am doing this but my uncle knows this. By not going in market does not effect factory sale or my uncle's sale . Am i allowed to take salary or not ?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.

If the company conditioned on you to assist in sales besides loading bread, cakes and biscuits in the bus, then you are obliged to fulfil the conditions of the contract. Allaah Says (what means): {O you who have believed, fulfil [all] contracts}[Quran 5:1]. Furthermore, the Prophet said: "The Muslims must fulfill their conditions." [Abu Daawood and At-Thirmithi]

It might be that the purpose of the company in you helping your uncle is to supervise him, as he will not dare to cheat if he is in the presence of another worker of the company. It might be also that two people selling the goods is better for their promotion than if the sale is done only by one person, and it could be for other reasons.

Anyway, it is not permissible for you to fail to fulfil the conditions of your work unless the person in charge of the company gives you permission to do so.

Therefore, you should repent to Allaah and assist your uncle in selling the goods, because the wages which you take from this job are forbidden for you unless you fulfil the conditions. 

Allaah Knows best.