posting icons

hi. I'm new here. I am also very much new to making any type of graphics on the computer :)

I feel like a total idiot asking this question (the answer is probably really obvious, I'm just not getting it), but I was wondering if somebody could please tell me how to post icons/wallpapers/any picture in my journal. When ever I try to click the "post image" button, this "javascript application" window pops up, asking me for a url to my pictures. I have no idea what to do. I also tried copying and pasting the images into my journal, but that did not work. I would be very greatful (sp? lol) if somebody could help me. I am really sorry for bothering ya'll. btw, this community is awesome--the memories section really helped me. If it matters, I use psp9

thankyou again :)