title: Open crystal report with subreport c# Issue
body: <p>While I'm using VS2010 to create crystal report, add a sub report, when I have link up 2 report by master table field. The crystal report in sub report will auto create the parameter field inside.</p>
  
  <p>While I come back to vs2010, and write the below code</p>
  
  <pre><code>_Cnn.Open();
  SqlCommand _cmd = new SqlCommand("SELECT ID, STUDENTNAME, AGE FROM CLASSMASTER", _Cnn);
  SqlDataReader _reader = _cmd.ExecuteReader();
  DataTable _dt1 = new DataTable();
  _dt1.Load(_reader);
  _cmd = null;
  _reader = null;
  
  _cmd = new SqlCommand("SELECT STUDENTID, NAMEBOO FROM LIBARYSRC", _Cnn);
  _reader = _cmd.ExecuteReader();
  DataTable _dt2 = new DataTable();
  _dt2.Load(_reader);
  ReportDocument _Report = new ReportDocument();
  string _report = @"reports\classreport.rpt";
  _Report.Load(_report);
  _Report.SetDataSource(_dt1);
  _Report.OpenSubreport("subreport").SetDataSource(_dt2);
  
  crv.ReportSource = _Report; // crv is report viewer control
  </code></pre>
  
  <p>The report viewer always prompt for ask input value of that parameter field. But when I go to vs2010 report design to preview, it is no problem, how to prevent this prompt?</p>
  
  <p>Thanks for your help.</p>