Forms :: Retrieving Images From File System

I am trying to retrieve images from the file system, but the open dialog box is not popping up for me to choose which file i want. It does nothing gives no error. Just says record 1/1 on the message bar at runtime.

I have two blocks on the module. One is the lobs_table block and the other is the control block. On the control block i have a when-button-pressed trigger on an item. And here is the code below.

Declare
jpg_image_dir VARCHAR2(100) := 'C:UsersajayiaDesktopMe_pics';
photo_filename VARCHAR2(100);
BEGIN
:System.Message_Level := '25';
[code]......

I don't know the code to use to get forms to bring up the open dialog box.