title: Passing the variable to another Form
body: <p>I got Form1 with some variables and I want to pass it to another Form3 where I'll use it. So I have two questions.</p>
  <ul>
  <li><p>How can I get access to the variable in another form? I suppose it will
  be similar to</p>
  <pre><code>var newIdList:= Form1.idList
  </code></pre>
  </li>
  <li><p>When var idList get value in</p>
  <pre><code>  procedure TForm1.Button1Click(Sender: TObject);begin
    idList:=strtoint(edit1.text);
    end
  </code></pre>
  <p>and I show new form in another can I still get value in <code>idList</code>?</p>
  <pre><code>procedure TForm1.Button2Click(Sender: TObject); 
  begin
  form1.hide;
  form3.show;
  end
  </code></pre>
  </li>
  </ul>
  <hr />
  <pre><code>    unit Unit1;
      
      interface
      
      uses
        Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
        Dialogs, StdCtrls, ComCtrls;
      
      type
        TForm1 = class(TForm)
          PageControl1: TPageControl;
          TabSheet1: TTabSheet;
          TabSheet2: TTabSheet;
          TabSheet3: TTabSheet;
          Label5: TLabel;
          Edit3: TEdit;
          Edit2: TEdit;
          Button3: TButton;
          Edit4: TEdit;
          Button2: TButton;
          Button1: TButton;
          Edit1: TEdit;
          Label1: TLabel;
          Label3: TLabel;
          Label2: TLabel;
          Edit5: TEdit;
          Label7: TLabel;
          Label6: TLabel;
          Button4: TButton;
          ListBox1: TListBox;
          procedure FormCreate(Sender: TObject);
          procedure Button1Click(Sender: TObject);
          procedure Button2Click(Sender: TObject);
          procedure Edit4Click(Sender: TObject);
          procedure Button3Click(Sender: TObject);
          procedure Edit1Click(Sender: TObject);
          procedure Button4Click(Sender: TObject);
      
        private
          { Private declarations }
        public
          { Public declarations }
          idList,imieList,nazwiskoList,adresList: TStringList;
        end;
      
      var
        Form1: TForm1;
        plik:TStringList;
        tempPlik:TextFile;
        st:string;
        linia_klient,linia_video:array[0..20] of string;
        id:integer;
      
      implementation
      
      uses Unit3;
      
      {$R *.dfm}
      
      .
      .
      .
      
      procedure TForm1.FormCreate(Sender: TObject);
      var i:integer;
      begin
      Edit1.Text:='Witaj, Podaj ID klienta';
      Label1.Caption:='ID Klienta';
      idList:=TStringList.Create;
      imieList:=TStringList.Create;
      nazwiskoList:=TStringList.Create;
      adresList:=TStringList.Create;
      
      if (FileExists('idList.txt')=true) then idList.LoadFromFile('idList.txt') else idList.SaveToFile('idList.txt');
      if (FileExists('imieList.txt')=true) then imieList.LoadFromFile('imieList.txt') else imieList.SaveToFile('imieList.txt');
      if (FileExists('nazwiskoList.txt')=true) then nazwiskoList.LoadFromFile('nazwiskoList.txt') else nazwiskoList.SaveToFile('nazwiskoList.txt');
      if (FileExists('adresList.txt')=true) then adresList.LoadFromFile('adresList.txt') else adresList.SaveToFile('adresList.txt');
      
      AssignFile(tempPlik,'video.txt');
      Reset(tempPlik);
      i:=0;
      While Not Eof(tempPlik) do
        begin
          Readln(tempPlik,linia_video[i]);
          inc(i);
        end;
      
      CloseFile(tempPlik);
      end;
      
      
      
      procedure TForm1.Button4Click(Sender: TObject);
      begin
        //Form1.Hide;
        Form3.Show;
      end;
      
      end.
  
  
  
  unit Unit3;
  
  interface
  
  uses
    Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
    Dialogs, StdCtrls;
  
  type
    TForm3 = class(TForm)
      Button1: TButton;
      Edit1: TEdit;
      Edit2: TEdit;
      Edit3: TEdit;
      Label1: TLabel;
      Label2: TLabel;
      Label3: TLabel;
      Label4: TLabel;
      procedure Button1Click(Sender: TObject);
      procedure FormShow(Sender: TObject);
  
  
    private
      { Private declarations }
    public
      { Public declarations }
    end;
  
  var
    Form3: TForm3;
  
  implementation
  
  uses Unit1;
  
  {$R *.dfm}
  
  procedure TForm3.Button1Click(Sender: TObject);
  begin
  Form3.Hide;
  //Form1.Show;
  end;
  
  
  
  procedure TForm3.FormShow(Sender: TObject);
  begin
  
  Label4.Caption:= intToStr(idList.Count);
  end;
  
  end.
  </code></pre>