How do I buy more space for attachments?

Seems I can only upload one file before it gets full, and I can't find any option anywhere.

Thanks..

I am not even ready to start charging yet, so this is not an option at this point. You should have 100 megs of space, so can you tell me exactly how much space you have used, and how much space the system is reporting you have left? You can find this information on your personal profile in the network.