Go to the reply box, click "Go Advanced"
You will see the paperclip to the right of the smilely face.
Click that and a box will come up to attach photos.
Click "browse..." to search your photos.
Then click "upload" next to the bottom "browse..." box to upload them on here.
If you reclick the paperclip you can see the file number/names.
If you click one of them the will attach to where the cursor is.
Make sure they are not too big or they won't load.