function doCalc() {
var spread = FpSpread("FpSpread1");
var rc = spread.GetRowCount();
var total = 0;
for (var i = 0; i < rc - 1; i++) {
var value = parseFloat(FpSpread1.GetValue( i, 0 ));
total += value;
}
if (!isNaN(total))
spread.SetValue(n-1, 0, total, true);
}