The problem is this line in your code.
var <font color='#ff0000'>"totaal"</font>=
You have double quotes wrapping the variable name which will cause a syntax error, it needs to be
var totaal =
Also your above code is quote verbose, you could easily cut a huge chunk of it out by re-factoring all your IF and parseFloat statements into array so only the field names are specified instead of all the code you currently have.