So far this tutorial has relied on just two methods of output;
The function used thus far have all been highly unobtrusive and do not do anything but allow debugging. The
document.write is another very useful debugging output method.
Another form of this is the is
document.writeln which will write a line to the document:
document.write and the
document.writeln functions will overwrite any existing HTML in the document. and should only be used for debugging purposes.
window.alert function is a formalised version of the