inputs:
FastLength( 12 ),
SlowLength( 26 ),
MACDLength( 9 ) ;
Plot1( MACD( Close, FastLength, SlowLength ), "MACD" ) ;
Plot2( XAverage( Plot1, MACDLength ), "MACDAvg" ) ;
Plot3( Plot1 - Plot2, "MACDDiff" ) ;
Plot4( 0, "ZeroLine" ) ;
{ Alert criteria }
if Plot3 crosses over 0...