AddFormField

Hi, I'm having problems doing POST.
Actually, I have an application that I need to post severlal info.
When I do the next, nothing happend.

paramData := TIdMultiPartFormDataStream.Create;
         paramData.AddFormField('wizardstate', 'CREATE_NEW');
         paramData.AddFormField('carid', carid);
         paramData.AddFormField('groupid', groupid);
         paramData.AddFormField('countryid', 'es');
         paramData.AddFormField('lang', 'es');
         paramData.AddFormField('save', 'Save and Continue» »');
try
sHTML:=IdHTTP1.Post(TheUrlWithTheScript, ParamData);
except
ShowMessage(intToStr(IdHTTP1.Response.ResponseCode));
.
.
.

Somebody can help me

Thanks in  adeventage
Yassel, from Argentina