I want to know what does Islam says about black magic.. and how can one easily diffrentitate between a wehm and sihr... or how could we find out that someone is the victim of Black magic..

How does magic work

He why guys. I had an affair of 5 years with my boyfriend... I was told by close friend of his he is trying some black magic on me... so that I should always remember him and he created mental block on my mind... can this be true... because when my parents came to know that he is worth...