JavaScript:Interactive Help Desk

Instructions
On this page you can post some JavaScript code that you are having trouble with.
 * Please keep the code "simple" concentrating on the problem ... not a lot of code with a "small" problem.
 * Post a tweet including the #vmvwiki tag so that we know there is a problem waiting to be solved.
 * Paste the following wiki code when you edit, and put your code where shown.

Posting reward scheme
The rules here are:
 * if it is a complex problem, and you solve it you should be rewarded with a small choc from the person posting, however
 * if it is easy to solve a more substantial chocolate "gift" (like a large chocolate fish would be nice :)

Problem 6: A window open causes a JavaScript error
You have entered the following code

and it doesn't work.

Problem 5: Adding two numbers js file
one.html

When Calculate button clicked - Error: Line 8, Character 5, Object expected

Problem 4: Linked js file
one.html

one.js