Bug: Sign and colour coding live updates to variance in monthly logs

The JavaScript {\tt updateVariance} function, which updates the variance field when a weight entry is changed, had two problems. First, it did not round the variance to the usual one decimal place before deciding whether it was positive, negative, or zero; consequently, it could consider a value which displayed as ``0.0'' as signed and prefix a sign to the number. Second, if the variance was zero, it was displayed in red as opposed to black, as the CGI form generation does. Live variance updates from the JavaScript code are supposed to display in colour according to their sign. This works in competently implemented browsers such as Firefox and Opera, but not in Exploder. So far, I have not found any work-around to fix this, so, at the moment, live updates to the variance will always display in black in that regrettable browser.