User blog:PrincessBubblegum13/How do you add a picture to a userbox thingy?

Im trying to make a userbox and I know how...but i dont know how to add a picture....in the example it has a code, but where do u get that from? I would like a pcture of marceline but I dont know how to add the specific picture :)

Please help me....

PrincessBubblegum13 19:55, July 28, 2011 (UTC)PrincessBubblegum13