SELECT IFNULL(ROUND(SUM(BillingAmount)-SUM(RecAmount)),0) OutStadningAmount
                                                                       FROM (SELECT IFNULL(SUM(IF(plos.`IsSampleCollected`='R',0,plos.`PCCInvoiceAmt`)),0)  BillingAmount,0 RecAmount FROM `patient_labinvestigation_opd_share` plos
                                                                       INNER JOIN `f_ledgertransaction` lt ON lt.`LedgerTransactionID`=plos.`LedgerTransactionID` 
                                                                       AND IFNULL(plos.`InvoiceNo`,'')=''
                                                                       INNER JOIN f_panel_master fpm ON fpm.`Panel_ID`=lt.`Panel_ID` 
                                                                       WHERE fpm.`InvoiceTo`=1015
                                                                       GROUP BY fpm.`InvoiceTo`
                                                                       UNION ALL
                                                                       SELECT SUM(im.ShareAmt)  BillingAmount,0 RecAmount FROM invoicemaster im
                                                                       WHERE im.PanelID=1015 AND im.IsCancel=0
                                                                       GROUP BY im.`PanelID`
                                                                       UNION ALL
                                                                       SELECT 0 BillingAmount,SUM(ReceivedAmt) RecAmount 
                                                                       FROM invoicemaster_onaccount io 
                                                                       WHERE io.Panel_ID=1015 AND io.IsCancel=0 AND io.Type='ON ACCOUNT' ) t