.Net windows application, Presentation layer and Business logic layer

Question

How can I access presentation layer controls (Cristal report viewer control) in Business logic layer.

Eg;

public ReportDocument showObj(object asd,string reportName)

{

   Form asw = (Form)asd;

   string sPath;

   sPath = System.IO.Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);

   sPath = sPath + @"\" + reportName;

   ReportDocument cr=new ReportDocument();

   //cr.Load(sPath);

   //cr.SetDatabaseLogon("JISH","YOURWISH");

   return cr;

}

Thse function is written in the business logic layer. Here, how can i access the presentation layer's control name?

(suppose in presentation layer -> objFrmReportviewer.crv.ReportSource="")

Advance Thanks.

Jimish