intraWeb 保存Excel表

try
ExcelApplication1.Connect;
ExcelWorkbook1.ConnectTo(ExcelApplication1.Workbooks.Add(EmptyParam,0));
ExcelWorksheet1.ConnectTo(ExcelWorkbook1.Worksheets.Add(EmptyParam,EmptyParam,EmptyParam,EmptyParam,0) as _worksheet);
except
webapplication.ShowMessage('服务器端excel启动失败！');
end;
//------------------------------------

// ds:=datamodule1.ds;
with ExcelWorksheet1.Cells do
begin
cells.Item[1,1]:='资料管理中心报表（查询结果）';
cells.Item[2,1]:=datetoStr(now);
for i:=0 to ds.FieldCount -1 do
cells.Item[3,i+1]:=ds.fields[i].DisplayLabel;
r:=4;
ds.First;
repeat
for i:=0 to ds.FieldCount -1 do
Cells.Item[r,i+1]:=ds.fields[i].Value;
r:=r+1;
ds.Next;
until ds.Eof;
end;

s:=TIWServerController.NewCacheFile('ggg');
s:=change_postfix(s,'xls');
// ExcelApplication1.Visible[0]:=True;
// ExcelWorkSheet1.PrintPreview;


if FileExists(s) then
DeleteFile(s);

ExcelWorkSheet1.SaveAs(s); ExcelApplication1.Quit;
ExcelWorkSheet1.Disconnect;
ExcelWorkbook1.Disconnect;
ExcelApplication1.Disconnect;
abort;

s:=WebApplication.URLBase + '/cache/' + ExtractFilename(s);
if IWCheckBox1.Checked then
begin
//s:='NewWindow("'+s+'", "","resizable=yes,toolbar=yes,scrollbars=yes");';
s:='NewWindow("'+s+'", "","");';
self.AddToInitProc(s);
end ;{else begin
with TformMainReport.Create(webapplication) do
begin
IWframe1.src:=s;
show;
end;
free;
end; }

错误发生在红色地方，保存出错，知道的请帮忙