calculator example broken, proposal for fix

Hi all

Don't know who to address for a fix in the calculator example:

Line 27 in calculator.html from

getElement('output').innerHTML = expression;

to

document.getElementById('output').innerHTML = expression;

The calculator example is in my opinion a beauty and illustrates a few 
LivePage concepts in a very minimalistic but obvious way. It's been 
broken for quite some time and deserves to be fixed :-))

Thxs, We