'FilterSubGrid' is undefined at eval code (eval code:1:1)

hey buddies,

   I am stuck in this error:  'FilterSubGrid' is undefined at eval code (eval code:1:1)

my task is to filter grid using second filter

plz help me .below is my code:

function FilterSubGrid()
{ 
 debugger; 
 var rowData = [5]; 
 var gridOfPrescription = window.parent.document.getElementById('Prescriptions');
 var filteredRecordCount = Xrm.Page.getControl('diseaseGrid').getGrid().getTotalRecordCount();
 
 for(int i = 0; i < filteredRecordCount ; i++)
  {    
   rowData[i] = Xrm.Page.getControl('diseaseGrid').getGrid().getRows().get(0).getData().getEntity().getAttributes().get('new_disease').getValue()[i].id;
  }
 var fetchXmlForPrescription = "<fetch version='1.0' output-format='xml-platform' mapping='logical' distinct='false'>" +
           "  <entity name='new_prescription'>" +
           "    <attribute name='new_prescribedon' />" +
           "    <attribute name='new_patientname' />" +
           "    <attribute name='new_suggestion' />" +
           "    <attribute name='new_weightofpatient' />" +
           "    <attribute name='new_patientname' />" +
           "    <attribute name='new_prescribedbydoctor' />" +
           "    <attribute name='new_issueof' />" +
     "    <attribute name='new_disease' />" +
           "    <order attribute='new_name' descending='false' />" +
           " <link-entity name='new_patientdisease' from='new_disease' to='new_disease'>"+
     "  <filter type='or'>"+
           "   <condition attribute='new_disease' operator='eq' value='" +rowData+ "' />"+
     "  </filter>"+
     " </link-entity>"+
           "  </entity>" +
           "</fetch>";
  
  gridOfPrescription.control.SetParameter("fetchXml",fetchXmlForPrescription);
        gridOfPrescription.control.refresh();
}