How do I post a photo?

I select attachments, select my photos, re size them but all I get is a red notice telling me,

NOTE: If you had an Attachment in your post, you will need to reselect the Attachment again in the Browser Box for security reasons.

What do I do next?

Just make a photobucket.com account and upload your pictures there. then you just take the link and put it in your post. it's also nice because if you go to someone elses house you can access it (photobucket) over the internet and show them.