Get value from Javascript to Label

[matija]

In javascript I have a function that returns ID. 
I want to read this value from HTML javascript and display it on the Label.

procedure TMainForm.IWAppFormCreate(Sender: TObject);
begin

AddToInitProc('function GetId() { return 5; }');

end;


procedure TMainForm.IWAppFormShow(Sender: TObject);
begin
IWLabel1.Caption:= Here This ID from function GetId -> 5
end;