Uploading pic to forum

I've been using iOS for awhile, but recently bought a mini and still learning OSX. I'm trying to upload a pic to a forum using an image uploader. I found the pic in my files but it is greyed out and I'm unable to select it.

I've done this before using a MB, so I'm thinking there is a setting that I am missing. I've searched through Safari and iPhoto but I can't find the right one. Any ideas what I'm overlooking?

Thank you

p.s. I'm running Mountain Lion.

Thank you. I didn't see the attachment icon, was using the image uploader.

I got the image attached and uploaded, then closed window. Clicked on attachment again - manage attachment and it shows photo.jpg. Preview post only shows text, not the image. Is this correct?

Nevermind just answered my own question.

Thanks for your help.