title: Call Button1Click in Form1/Unit1 from Unit2
body: <p>I've downloaded Delphi XE7 and having some problems with accessing another Units...
  I need to call procedures from another units, so I'll give a very basic illustration, simple program... 
  This is code from main Unit1 with form and button1:</p>
  
  <pre><code>unit Unit1;
  interface
  uses
    Windows, Messages, SysUtils, Variants, Classes, Graphics,
    Controls, Forms, Dialogs, StdCtrls, Unit2;
  type
    TForm1 = class(TForm)
      Button1: TButton;
      procedure Button1Click(Sender: TObject);
    private
      { Private declarations }
    public
      { Public declarations }
    end;
  
  var
    Form1: TForm1;
  
  implementation
  {$R *.dfm}
  
  procedure TForm1.Button1Click(Sender: TObject);
  begin
  ShowMessage('Hello');
  end;
  
  end.
  </code></pre>
  
  <p>And this is the code from Unit2:</p>
  
  <pre><code>unit Unit2;
  interface
  implementation
  uses Unit1;
  end.
  </code></pre>
  
  <p>Now, how is it possible to make procedure Button1Click like in Unit2 to showmessage let's say HelloFromUnit2 when button1 on form1 is clicked? Unit2 is codeUnit without anything.. </p>