macro 'Subtract Background Image from an NIH-Image Stack'

var
		i:integer;
begin
		if nSlices=0 then begin	{Check if there is a stack open}
		   PutMessage('Sorry, this macro only works on stacks.'); 
		   exit;
		end;
	PutMessage('Open the background image you wish subtracted from the stack.');
	Open('');													{Lets you go and find the background image}
	SelectAll;											{Selects the Background image}
	Copy;															{Copies the Background image to the clipboard}
	Dispose;
		for i:= 1 to nSlices do begin
		SelectSlice(i);
		ShowPasteControl;
		Paste;
		SetOption; Subtract;			{Subtract the stored background from each slice in the stack}
		end;
	PutMessage('Save the subtracted stack as a new stack.');
	SaveAs('');										{Allows you to save the new stack under a new name, keeping the} 				
	Dispose;												{original intact}
end;