(PECL ps >= 1.1.0)
ps_add_note — Adds note to current page
Adds a note at a certain position on the page. Notes are like little rectangular sheets with text on it, which can be placed anywhere on a page. They are shown either folded or unfolded. If unfolded, the specified icon is used as a placeholder.
此说明在文档被打印或显示时不可见，只在文档用 Acrobat Distiller 或 Ghostview 转换成 PDF 时显示。
Resource identifier of the postscript file as returned by ps_new().
The x-coordinate of the lower left corner.
The y-coordinate of the lower left corner.
The x-coordinate of the upper right corner.
The y-coordinate of the upper right corner.
The text of the note.
The title of the note as displayed in the header of the note.
The icon shown if the note is folded. This parameter can be set to comment, insert, note, paragraph, newparagraph, key, or help.
If open is unequal to zero the note will be shown unfolded after opening the document with a pdf viewer.
成功时返回 TRUE， 或者在失败时返回 FALSE.