Splitting the script file

I am trying to have script separated by forms and separate script to maintain common functions/procedures.

But its showing error. Have all the 3 files in 'Script' folder of the project. Please advice me on this.

---------------
file - script.pas
----------------
uses 'form1.pas', 'common.pas';
//uses 'common.pas';

var
  sHello: string;

begin
  // just for example
  sHello := 'Script said hello!';
  HelloWorld(sHello);
end.     

----------------
file - common.pas
----------------
procedure HelloWorld (s: string);
begin
  ShowMessage(s);
end;

---------------
file - form1.pas
----------------
uses 'common.pas';

procedure cb_Button1_OnClick (Sender: TObject; var Cancel: boolean);
var
begin
     HelloWord('Hello from form1');
end;