SQL> declare
  2  pName varchar2(5):='pen';
  3  stock number:=10;
  4  qty number:=&qty;
  5  unitp number:=10;
  6  totalc number;
  7  rem number(5);
  8  begin
  9  totalc:=qty*unitp;
 10  rem:=stock-qty;
 11  if stock>qty then
 12  dbms_output.put_line('Thanks for shopping');
 13  dbms_output.put_line('you ordered '||qty ||'pens');
 14  dbms_output.put_line('product name: '||pName);
 15  dbms_output.put_line('remaining stock: '||rem);
 16  dbms_output.put_line('total price: '||totalc);
 17  else
 18  dbms_output.put_line('out of stock');
 19  end if;
 20  end;
 21  /
Enter value for qty: 5
old   4: qty number:=&qty;
new   4: qty number:=5;
Thanks for shopping                                                             
you ordered 5pens                                                               
product name: pen                                                               
remaining stock: 5                                                              
total price: 50                                                                 

PL/SQL procedure successfully completed.