Upload attachment, set maximum allowed per attachment

< attachment_upload_button = "picturebox.gif">
< maximum_allowed_size_per_file = "1234 KB">
< attachment_mention_box = "box.gif";
< /attachment_mention_box>
< /maximum_allowed_size_per_file>
< /attachment_upload_button>

^ with no spaces is what I had in mind that may or may not work.

Basically I want to know how to code
upload attachment, set maximum allowed of data example 1234 KB of data per file
please, thank you.

Please feel free to post coding, codings etc. that will work, thank you.