Displaying Size of image in Oracle Forms

i m using get_file_name built-in on when-button-pressed trigger and save image in database BLOB datatype, every thing is going smoothly but i have a requirement that if load size is more then 25 kb then user unable to save this image with
message ('Image Size is more then 25kb ');

i got some online help can any one exaplain me this code

CREATE TABLE TEMP_PHOTO ( ID NUMBER(3) NOT NULL, PHOTO_NAME VARCHAR2(50), PHOTO BLOB );

CREATE OR REPLACE PROCEDURE load_file ( p_id NUMBER, p_photo_name IN varchar2)
IS  
src_file BFILE;
dst_file BLOB;
lgh_file BINARY_INTEGER;  
BEGIN  
src_file := bfilename('PHOTO_DIR', p_photo_name);
  -- insert a NULL record to lock
 INSERT INTO temp_photo  (id, photo_name, photo) VALUES (p_id , p_photo_name ,EMPTY_BLOB())  RETURNING photo INTO dst_file;  
SELECT photo   INTO dst_file  FROM temp_photo  WHERE id = p_id  AND photo_name = p_photo_name  FOR UPDATE;  
dbms_lob.fileopen(src_file, dbms_lob.file_readonly);  
lgh_file := dbms_lob.getlength(src_file);
dbms_lob.loadfromfile(dst_file, src_file, lgh_file);
UPDATE temp_photo   SET photo = dst_file  WHERE id = p_id  AND photo_name = p_photo_name;

 dbms_lob.fileclose(src_file);  
END load_file;

The procedure created successfully

Now,
execute load_file(1,'Sunset.jpg'); gives me the following error :

ERROR at line 1:
ORA-22288: file or LOB operation FILEOPEN failed
No such file or directory
ORA-06512: at "SYS.DBMS_LOB", line 805
ORA-06512: at line 6


Thanks in advance