Script Error One of the scripts for this record has caused an error. For more details, download the log file. ReferenceError: 'FilterSubGrid' is undefined at eval code (eval code:1:1)

buddies ,

this is my code can u solve my error plz:

function FilterSubGrid()
 {
 debugger;
  // refer the subgrid

//Prescriptions is my unique name of subgrid
 var testGrid = window.parent.document.getElementById(“Prescriptions”));

 if (testGrid == null)
   {
  setTimeout(function () {FilterSubGrid(); }, 2000);
  return;
   }
 else
   {
   // fetch xml code using User operator
   var fetchXml = "<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' />"+
      "    <order attribute='new_name' descending='false' />"+
      "    <filter type='and'>"+
      "      <condition attribute='new_issueof' operator='eq' uiname='Dentist' uitype='new_specialityofdoctor' value='{A12E3098-CC5C-E711-8125-5065F38C1521}' />"+
      "    </filter>"+
      "  </entity>"+
      "</fetch>";

   if (testGrid.control != null)
     {
    testGrid.control.SetParameter(“fetchXml”, fetchXml);
    testGrid.control.refresh();
     }
   else
     {
      setTimeout(FilterSubGrid, 500);
     }
   }
 }