SweeneyLovett

I am new to Second Life and just got my house. I've been trying to find help with hanging posters. I try to drag it to the wall or just drag it out and I can't do that. I go to a sandbox to try and pull it out and I can't do that. I right click and open and it opens the picture. There's no way that I can find to drag them out. When I try to drag it it gives me a small lock icon when I get to the wall. I've searched tutorials and most other places and I just can't find a solution. I would appreciate the help, thank you. I've included a pic of the wall I'm trying to hang it on.