UNIX for Dummies Questions & Answers

I use a forms application where I develop the forms(Oracle 6i) in windows server and compile(Oracle 9i) the same in Unix server.
The whole forms application executables are placed in Unix.
My requirement is to upload data from excel sheet to oracle tables using Oracle forms. I have developed the form.
The scenario is when I click on the UPLOAD button in the form it should browse for the file to be uploaded.
With windows application its working but not with the unix application.

I want the same thing for the application in Unix server also. In the Unix application when I click on the UPLOAD button nothing is happening

The code written behind the UPLOAD button is
-----------------------------------------------------------------------

Code:

DECLARE 
   lv_dirname   VARCHAR2(255); 
   lv_filename  VARCHAR2(255); 
BEGIN 
        
   tool_env.getvar('DEMO20', lv_dirname); 
   lv_dirname  := 'c:\'; 
   lv_filename := get_file_name(lv_dirname, NULL, 'ESN List (*.txt)|*.txt|' ); 
   IF lv_filename IS NOT NULL THEN 
      :FILENAME := lv_filename; `
   END IF; 
    
    
END;

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What changes I have to do for the same thing to happen in forms which is connected to unix server.
I want the equivalent code which does the same for the forms placed in the Unix server
Please help on this issue.