c# - Failed to retrieve data from database -

i'm trying use crystal reports , connect stored procedure takes 2 parameters.

the user fills 2 text boxes , i'm trying pass these parameters stored procedure.

but error

failed retrieve data database

here code

private void button1_click(object sender, eventargs e) {         if (check(txtfrmdt, txttdt))         {             cryrpt = new reportdocument();             crtablelogoninfos = new tablelogoninfos();             crtablelogoninfo = new tablelogoninfo();             crconnectioninfo = new connectioninfo();              cryrpt.load("e:\\users\\mostafa\\documents\\visual studio 2013\\projects\\sales , inventory system\\sales , inventory system\\inventory_report.rpt");              parameterfields = new crystaldecisions.shared.parameterfields();             parameterfield = new parameterfield();             parametervalue = new parameterdiscretevalue();              parameterfield.name = "@param1";             parametervalue.value = txtfrmdt.text;             parameterfield.currentvalues.add(parametervalue);             parameterfields.add(parameterfield);             cryrpt.setparametervalue("@param1", parametervalue);              parameterfield.name = "@param2";             parametervalue.value = txttdt.text;             parameterfield.currentvalues.add(parametervalue);             parameterfields.add(parameterfield);             cryrpt.setparametervalue("@param2", parametervalue);              crconnectioninfo.servername = "mostafa-pc";             crconnectioninfo.databasename = "sales , inventory system";             crconnectioninfo.userid = "sa";             crconnectioninfo.password = "1";              crtables = cryrpt.database.tables;              foreach (crystaldecisions.crystalreports.engine.table crtable in crtables)             {                 crtablelogoninfo = crtable.logoninfo;                 crtablelogoninfo.connectioninfo = crconnectioninfo;                 crtable.applylogoninfo(crtablelogoninfo);             }              crystalreportviewer1.reportsource = cryrpt;             crystalreportviewer1.refresh();         } } 

what should do?