use below code:
if (!IsPostBack)
{
string strEmpUID = "0";
string strLocationID = "0";
string strDepartmentID = "0";
MyReportViewer.ProcessingMode = Microsoft.Reporting.WebForms.ProcessingMode.Remote;
string username = System.Configuration.ConfigurationManager.AppSettings["ReportViewerUser"].ToString();
string password = System.Configuration.ConfigurationManager.AppSettings["ReportViewerPassword"].ToString();
string domain = System.Configuration.ConfigurationManager.AppSettings["ReportViewerDomain"].ToString();
MyReportViewer.ServerReport.ReportServerCredentials = new MyReportServerCredentials();
MyReportViewer.ServerReport.ReportServerUrl = new Uri(@"http://server/ReportServer");
MyReportViewer.ServerReport.ReportPath = @"/Report Project2/Report1";
MyReportViewer.ShowParameterPrompts = false;
MyReportViewer.ShowPrintButton = true;
Microsoft.Reporting.WebForms.ReportParameter[] RptParameters = new Microsoft.Reporting.WebForms.ReportParameter[3];
RptParameters[0] = new Microsoft.Reporting.WebForms.ReportParameter("EmpUID", strEmpUID);
RptParameters[1] = new Microsoft.Reporting.WebForms.ReportParameter("LocationID", strLocationID);
RptParameters[2] = new Microsoft.Reporting.WebForms.ReportParameter("DepartmentID", strDepartmentID);
MyReportViewer.ServerReport.SetParameters(RptParameters);
MyReportViewer.ServerReport.Refresh();
}