Dateizugriff/Verwaltung funktionieren nicht

[julchen]

Delphi-Quellcode:

unit form;

uses SysUtils;

interface

procedure formular;

implementation

uses unit6;

procedure formular;
var
        hhp, hhc, hhk, css, html: String;
begin
       Form1.PageControl1.ActivePage := Form1.TabSheet1;
       Form1.PageControl2.ActivePage := Form1.TabSheet7;
       Form1.Caption := 'project';
       Form1.JvFileListBox1.Mask := '*.hhp;*.hhc;*.hhk;*.css;*.html';

       hhp := ExtractFileExt(Form1.JvFileListBox1.FileName);
       If FileExists(hhp) = true then
       begin
         Form1.SetVisibleTabs([5,6]);
       end
         else
       begin
         Form1.SetVisibleTabs([1]);
       end;
         
end;