Buy and sell signals

Hi experts

Like helping me in past please help me to plot buy and sell signals on this afl code.
Note : Where green line end and red line starts down arrow should be their. In the same way when red line ends and green line starts up arrow should be their.

Thanks in Advance :
Afl code :

//------------------------------------------------------------------------------
//
// Formula Name: INTRADAY HEIKIN ASHI new
// Author/Uploader: ali
// E-mail: [email protected]
// Date/Time Added: 2006-09-22 19:07:15.
// Origin: a
// Keywords: INTRADAY HEIKIN ASHI new
// Level: advanced
// Flags: system
// Formula URL: http://www.amibroker.com/library/formula.php?id=714
// Details URL: http://www.amibroker.com/library/detail.php?id=714
//
//------------------------------------------------------------------------------
//
// INTRADAY HEIKIN ASHI new
//
//------------------------------------------------------------------------------

/*======================================================
FOREX INTRADAY HEIKIN ASHI + PIVOT POINTS
======================================================*/

//---- heikin ashi
HaClose = (O+H+L+C)/4;
HaOpen = AMA( Ref( HaClose, -1 ), 0.3 );
HaHigh = Max( H, Max( HaClose, HaOpen ) );
HaLow = Min( L, Min( HaClose, HaOpen ) );
xDiff = (HaHigh - Halow) * IIf(StrFind(Name(),"JPY"),100,10000);
barcolor = IIf(HaClose >= HaOpen,colorBrightGreen,colorRed);
PlotOHLC( HaOpen, HaHigh, HaLow, HaClose, "", barcolor, styleThick|styleDots );
// Plot(EMA(HaClose,9),"",colorWhite, styleLine);
// Plot(EMA(HaClose,18),"",colorBlack, styleLine);

_SECTION_BEGIN("Bollinger Bands");
P = ParamField("Price field",-1);
Periods = Param("Periods", 15, 2, 100, 1 );
Width = Param("Width", 2, 0, 10, 0.05 );
Color = ParamColor("Color", colorCycle );
Style = ParamStyle("Style");
Plot( BBandTop( P, Periods, Width ), "BBTop" + _PARAM_VALUES(), colorWhite, style);
Plot( BBandBot( P, Periods, Width ), "BBBot" + _PARAM_VALUES(), colorWhite, style);
_SECTION_END();