Analyse the code below void clicked ( ) { PurchLine tmpPurchLine; PurchLine updatePurchLine; PurchLine selectedRecord; Dialog dl; DialogField dlfTransdate; ; dl = new Dialog ( "Change confirmed date" ) ; dlfTransdate = dl. addFieldValue ( typeid ( "Transdate" ) , today ( ) , "Confirmed date" ) ; if ( dl. run ( ) ) { selectedRecord = PurchLine_ds. cursor ( ) ; for ( tmpPurchLine = PurchLine_ds. getFirst ( true ) ? PurchLine_ds. getFirst ( true ) : PurchLine_ds. cursor ( ) ; tmpPurchLine; tmpPurchLine = PurchLine_ds. getnext ( ) ) { ttsbegin ; SELECT FORUPDATE updatePurchLine WHERE updatePurchLine. PurchId == tmpPurchLine. PurchId && updatePurchLine. VendAccount == tmpPurchLine. VendAccount && updatePurchLine. LineNum == tmpPurchLine. LineNum && updatePurchLine. ItemId == tmpPurch...