cs= A_period+B_period+num_bars; //checksum used to see if parameters have been changed
if ((cs==prevcs)&&(commodt==Symbol())&&(frame==(Time[4]-Time[5]))&&((Bars-prevbars)<2)) startpar=Bars-prevbars; else startpar=-1; //params haven't changed only need to calculate new bar
commodt=Symbol();
frame=Time[4]-Time[5];
prevbars = Bars;
prevcs = cs;
if (startpar==1 | startpar==0) bar=startpar; else initDone = true;