Limit Rich Text Lite to JPG only?

Is there a way to limit the choices in a Rich Text Lite field to jpeg only? Preferably in the window that lets you choose the file. If not, can the file-name in the RTL field be referenced to perform a field valadation on?

Subject: You can get the filename of the attachment in script

Use the EmbeddedObjects property to get the attachment and notesEmbeddedObject.Source to get to the name of the attachment.

You can do this in a webquerysave agent.

Howard