救命！为什么TWordApllication.Selection总是空0x0000000？附代码....(50分)

var
Template,NewTemplate,ItemIndex,_WordDocumentType,_Visible,_FileName:OleVariant;
_InsertText : OleVariant;
begin
NewTemplate := False;
BigIndex := 0;
SmallIndex := 0;
//Template := ExtractFilePath(Application.ExeName) + 'Output.dot';
Template := EmptyParam;
//ShowMessage(ExtractFilePath(Application.ExeName) + 'Output.dot');
_WordDocumentType:=wdNewBlankDocument;
_Visible:=False;

PaperWord.Connect;
PaperWord.Documents.Add(Template, NewTemplate, _WordDocumentType,_Visible);
PaperWord.Selection.TypeText('');