$lastBooking=Sale::orderBy('id','DESC')->first();
             $year=date("Y");
             $invoice_no=10001;
             
             if(isset($lastBooking) && $lastBooking->invoice_no!=''){
                    $bookingNo=explode("/",$lastBooking->invoice_no);
                
                    if($year==$bookingNo[1]){
                        $invoice_no=$bookingNo[2]+1;
                    }
                  
             }   
             
             $invoice_no='AJ/'.$year.'/'.$invoice_no;