[amibroker] Determine Cumulative Profit from AFL

[dralexchambers]

I am running a backtest (futures mode) and am altering my position 
size according to the Cumulative Profit:

for (i=1; i<BarCount; i++)
{
        if (Buy[i]==1 AND Buy[i-1]==0))
                {Code here to alter position size
                }
}

How do I determine the current cumulative profit in this loop?

Thanks - alex