for ex.
you have 2 forms with units,
unit1
unit2
first one should look like
unit Unit1;
{$mode delphi}{$H+}
interface
uses
Classes, SysUtils, FileUtil, LResources, Forms, Controls, Graphics, Dialogs,
ComCtrls, StdCtrls,unit2,
....
thesecond one should look like
nit Unit2;
{$mode delphi}{$H+}
interface
uses
Classes, SysUtils, FileUtil, LResources, Forms, Controls, Graphics, Dialogs,
ComCtrls, StdCtrls;
....
implementation
uses unit1;