upload the attachment which is on ur computer likes pictures.  

1.Click the New post or Reply(not the fast post),input the Subject and the content .

2.under the textboard you can see the “Uploading New Attachments [+] [-]",

click the [+] you can upload more then 1 attachment by the same time , click the [-] just reduce it.

3.Upload ur attachments (A attachment’s size is Limited in 0-512KB ).