Please UseCodeTags the next time you want to post some code. Formatting the code properly would help to read it too.
Posting something else than the code would help too. For example, the complete stack trace of the error. In the sales class, you are calling super(productcode,price,productname), but there is no such constructor in the product class. (class names usually start with a capital letter).
when you call constructor/create object first super class constructor runs. In your case your super class constructor doesn't match argument. It means suppose you have a 2 classes as
Then here in child class there is constructor which takes only one argument as String. But in parent class Constructor takes argument as String and int. Parent (String name,int age) . So you must have to add constructor in Child class who has argument as String and int. like
same case in your program. In your progam in product class you had written constructor as
And in Sales class inside constructor you are providing only 3 argument as
Instead of that it requires 7 argument. Hope now it is clear to you.
Life is easy because we write the source code.....