Can't open WorkList

I try to open WorkListItem by the following code (this code run in ASP.NET )

SourceCode.K2ROM.Connection oK2Connection = new SourceCode.K2ROM.Connection();
SourceCode.K2ROM.Worklist oWorkList;
oK2Connection.Open(strK2Server);
oWorkList = oK2Connection.OpenWorklist("ASP");

And the result of oWorkList.Count return 0.

But when i checked in my WorkSpace. It have 16 ProcessInstances. In activities in ProcessInstances have the destination is <My Name>.

Why oWorkList.Count return 0?

Help me.

Thanks!