Changes made to handle ref invoice date null case in CDNUR section for offline excel file download

git-svn-id: http://15.206.35.175/svn/proteus/business-java/trunk@177836 ce508802-f39f-4f6c-b175-0d175dae99d5

webitm-gst/ibase/webitm/ejb/gst/GSTDataSubmitWizEJB.java

@@ -3800,7 +3800,7 @@ public class GSTDataSubmitWizEJB extends ValidatorEJB implements GSTDataSubmitWi
 								preGST = "";
 							}
 							
-							if(refInvDate.after(gstStartDate))
+							if(refInvDate!=null && refInvDate.after(gstStartDate))
 							{
 								sql = "SELECT TRAN_TYPE FROM GST_DATA_HDR WHERE DOC_NO = ? ";
 								pstmt = conn.prepareStatement(sql);