Do Genies exist?

I've been researching in genies and i've found out that their made from fire and are invisible. I have seen many people over the internet offering to give you the incantation to conjour a genie. At first it was kinda interesting, u no, u get to have ur own genie. But i have a lot of muslim friends and they've all told me that genies or Jinns(what they call them) are dangerous and you shouldn't try to make contact with them. Now I've made up my mind that i'm not going to risk it but i still want to know if they're evil or good. I now this Q might sound silly to some but if anyone knows any info on genies then please tell me. Thanks. luv u all for the answers. xxx