Math Notes
When you want to do math on a number
you get out of a text box you will want
to multiply it by 1 first. Otherwise you will
end up concatenating them.
if you wanted to add 4 and 5 you expect 9 but if you dont tell
javascript that 4 and 5 are numbers than it will
think they are text.
ie:
alert('a' + 'b') would alert "ab" together. (Try it)
now try to alert this:
alert('4' + '5') (Try it>)
now try alert('4'*1 + '5'*1) (Try it)
Other Things to look at
The Form Tag. Using forms in HTML with Javascript can be very powerful. In addition we have added the Submit button which is a special button that does whatever the form action is when clicked.Also we are using the JavaScript switch Statement.