fileUpload to DB

I want to upload files to database, but I faced with some problems. I used "fileUpload" component and I can upload .txt format only, regarding any other ones it does not work. In Chrome, there is an error "cannot find application", but in Mozzila Firefox there is no error appeared (no reaction), but also does not upload a file. I tried in another PC, it worked well. Can you help me with it? What am I supposed to do? There are Panel XML and code which I used. Thank you in advance.

Yerkin.

XML:

<panel preferredHeightPolicy="Dynamic">
  <tableLayout cellSpacing="5">
    <row heightPolicy="Dynamic">
      <cell hAlign="Full" vAlign="Full">
        <textLabel label="Upl File"/>
      </cell>
      <cell hAlign="Full" vAlign="Full">
        <fileUpload name="FileUploader" domain="DefaultBLOB"/>
      </cell>
    </row>
    <row heightPolicy="Dynamic">
      <cell hAlign="Full" vAlign="Full">
        <textLabel label="Id Lot"/>
      </cell>
      <cell hAlign="Full" vAlign="Full">
        <textField name="lot"/>
      </cell>
    </row>
    <row heightPolicy="Dynamic">
      <cell hAlign="Full" vAlign="Full">
        <textLabel label="Att Lot File Desc"/>
      </cell>
      <cell hAlign="Full" vAlign="Full">
        <textField name="FILE_DESC"/>
      </cell>
    </row>
    <row>
      <cell>
        <button label="Save" uploadOnEvent="buttonPress" uploadFrom="testUploadPanel.FileUploader">
          <events>
            <buttonPress action="fileUpload"/>
          </events>
        </button>
      </cell>
    </row>
  </tableLayout>
</panel>

Code:

procedure fileUpload
is
    id_file_test number;
    upl_file_name varchar2(50);
  begin

    id_file_test := att_lot_seq.nextval; 
    upl_file_name := api_component.getUploadedFileName('testUploadPanel.FileUploader');
    insert into t_att_files_lots(id_att_file, att_lot_file_name, att_lot_file, att_lot_file_desc, id_lot)
    values(id_file_test, upl_file_name, 
                         api_component.getValueBL('testUploadPanel.FileUploader'), 
                         api_component.getValueTX('testUploadPanel.FILE_DESC'), 
                         api_component.getValueTX('testUploadPanel.lot'));

    commit;

    api_dialog.setVisible('uploadDlg', 'N');
    api_datasource.executeQuery('T_ATT_FILES_1');      
end;