How to display image in oracle form

Question

I have created a Oracle form (Oracle 10g) to Insert and Display images to/from the Database . I stored the image as a BFILE in the database. So far, I've managed to insert the image into the database. I am able to display the image using the fields entered into the form directly from the directory by using READ_IMAGE_FILE , but this is not I want, I want to search the database for a file name (primary key) and display the result. Here's what happens when I click on LOAD_IMAGE:

Trigger of LOAD_IMAGE:

READ_IMAGE_FILE(
:IMAGE_TABLE.IMAGE_DIRECTORY || :IMAGE_TABLE.IMAGE_NAME_FORM ||'.' || :IMAGE_TABLE.IMAGE_TYPE,
'ANY',
'IMAGE_TABLE.IMAGE'
);

I've gone through Oracle documentation but it doesn't have any documentation for functions like read_image_file etc., So how to display the result by searching the database using the Image name entered in form rather than displaying from directory? Thanks in advance :)