从crystalreportviewer打印水晶报告

我通过crystalreportviewer在网页中显示了crystalreport，并且运行良好，但是当我按下工具箱中的打印"按钮以打印报告时，它只是对页面进行了后包装而没有任何动作.
这是我的代码:

I display a crystalreport in web page by crystalreportviewer , and I works well but when I press the print button in toolbox to print report it dosn''t do any action just postpack page.
here is my code:

DS_Reports DS_Rep = new DS_Reports();
DA_Users.Fill(DS_Rep, "Complaints");
Reports.UsersInfo Rep_Users = new Reports.UsersInfo();
Rep_Users.SetDataSource(DS_Rep);
Session["UserRep"] = Rep_Users;
Viewer_Users.ReportSource = Rep_Users;