delphi自动填写上传图片的问题 急！！！


以下是我的代码 我想实现的功能是自动填表后提交表单 可是表单是提交成功了 但照片没上传成功 
各位看下是哪出问题了
这个网站是 http://www.flixya.com/
有个账号 xiongya3333 密码 003365170  大家可以测试下 
上传图片的网页代码是
<form action='http://www.flixya.com/nav/process_photos' method='post' name='sphotos' enctype="multipart/form-data">procedure   TForm1.UpLoagFile(FileName:String);
var
obj:TIdMultiPartFormDataStream;
Url:String;
memStream:TMemoryStream;
begin
obj:=TIdMultiPartFormDataStream.Create;
memStream:=TMemoryStream.Create;
obj.AddFile('sphotos',FileName,'multipart/form-data');
IdHTTP1.Request.ContentType:=obj.RequestContentType;
obj.Position:=0;
Url:='http://www.flixya.com/nav/process_photos';
IdHTTP1.Post(url,obj);
end;
procedure TForm1.Button1Click(Sender: TObject);
var
Doc: IHTMLDocument2;
input: OleVariant;
HtmlWnd:IHtmlWindow2;
wenjian:IHTMLInputFileElement;
userinputelement:ihtmlinputelement;
HTMLTextAreaElement: IHTMLTextAreaElement;
leibie:IHTMLSelectElement;
s:string;
begin
   doc:=webbrowser1.document as ihtmldocument2;
     if not Assigned(doc) then
     exit;
     HtmlWnd:= Doc.parentWindow;
     if not Assigned(HtmlWnd ) then
     exit;
     wenjian:=(doc.all.item('file[]',0) as IHTMLInputFileElement);
     wenjian.value:='E:\熊亚\113.jpg';
     UpLoagFile('E:\熊亚\113.jpg');
     s:='submit_form()';
    HtmlWnd.execScript(s,'JavaScript');
     end;