service isapi

Question

function querydata(const ssqlcommand:string):string;
var
vdata:olevariant;
vobj:variant;
begin
 coinitialize(nil);
 try
 try
 vobj:=createoleobject('pdataserver.delphiadoserver');
 //vobj:=Codelphiadoserver.Create;
 vobj.querymydata(ssqlcommand,vdata);
 result:=vdata;
 vobj:=unassigned;
 except
 end;
 finally couninitialize();
 end;
end;  function  userindex(const msg: WideString;password,database,server,username,filepath:string): WideString;
begin
sql:='select top 200 from table';
 result:=querymydata(sql);
end;
为什么不能实现真正的多线程？querymydata是com+的接口，userindex 是webservice isapi的接口。请各位高手指点，高分求助，急！！！