Crystal Reports prompt issue on export: “The report you requested requires further information”

I have searched through forums for a solution but none seem to work for me.

I have an ASP Webform/MySql application which displays Crystal Reports.

The ones which do not require a user to enter a parameter display fine and I am able to click on export on the CR toolbar and download, e.g. .pdf format.

On the report that require a user to enter a parameter, the report renders fine but when I click on the export button, i get the prompt:

"The report you requested requires further information"

asking for DB login credentials. How can I avoid this?

My Code:

Aspx page:

......

<%@ Register Assembly="CrystalDecisions.Web, Version=13.0.2000.0, Culture=neutral, PublicKeyToken=692fbea5521e1304" Namespace="CrystalDecisions.Web" TagPrefix="CR" %>

.....

<div>

          <CR:CrystalReportViewer Width="960px" ID="CrystalReportViewer1" runat="server" AutoDataBind="true" />

</div>

protectedvoidPage_Load(object sender,EventArgs e)
{
         if(Request.QueryString["report"]!=null)
         {
                string reportToGet =Convert.ToString(Request.QueryString["report"]);

                switch(reportToGet)
                {
                        case"payslip":
                        PaySlip();
                        break;
                        case"pastpayslip":
                        PanelPastPaySlip.Visible=true;
                        break;  
                       default:
                       break;
                }
          }
   }

protectedvoid btnSearch_Click(object sender,EventArgs e)
{
      if(txtDate.Text!=null|| txtDate.Text!=string.Empty)
      if(DateTime.TryParseExact(txtDate.Text,"yyyy-MM-dd",CultureInfo.InvariantCulture,
      DateTimeStyles.None,out date))
      PastPaySlip();
}

private void PastPaySlip()

        {

            // Some code....

            PayMasterDataSetTableAdapters.pastpayslipcasualviewTableAdapter ta =

                new PayMasterDataSetTableAdapters.pastpayslipcasualviewTableAdapter();

            PayMasterDataSet.pastpayslipcasualviewDataTable dt = new PayMasterDataSet.pastpayslipcasualviewDataTable();

            ta.FillBy(dt, userId, businessId);

            cReport = new ReportDocument();

            string reportPath = Server.MapPath("~/Views/CasualLabour/Reports/PastPaySlip.rpt");

            cReport.Load(reportPath);

            cReport.SetDataSource((DataTable)dt);

            cReport.SetParameterValue("Date", date);

            cReport.SetDatabaseLogon("userID", "password", "server", "database");

            CrystalReportViewer1.ReportSource = cReport;

            CrystalReportViewer1.ReuseParameterValuesOnRefresh = true;

        }

I am using CR V. 13.0.9 and VS 2013 Update 2