Buy/sell signal in any ami broker chart code

Hello,
i have a question about how to write a buy sell signal in any of the AFL chart formula.If i write click on a chart i have this option to copy the formula of that particular chart (Edit Formula). Now i want to write a buy sell signal for this formula. Some one please help to do so. Thanks.
Below is one example of the chart formula:-




_SECTION_BEGIN("Price");
SetChartOptions(0,chartShowArrows|chartShowDates);
_N(Title = StrFormat("{{NAME}} - {{INTERVAL}} {{DATE}} Open %g, Hi %g, Lo %g, Close %g (%.1f%%) Vol " +WriteVal( V, 1.0 ) +" {{VALUES}}", O, H, L, C, SelectedValue( ROC( C, 1 )) ));
Plot( C, "Close", ParamColor("Color", colorDefault ), styleNoTitle | ParamStyle("Style") | GetPriceStyle() );
_SECTION_END();

_SECTION_BEGIN("Price Interpretation");
movshort = ParamField("Short Time MA", 8 );
movmed = ParamField("Mid Time MA", 9 );
movlong = ParamField("Long Time MA", 10 );
btop = ParamField("BBTop", 11 );
bbot = ParamField("BBBottom", 12 );
if( Status("action") == actionCommentary )
{
width = btop - bbot;
lslop = LinRegSlope( C, 30 ) + 100;
lslo = LLV( lslop, 90 );
lshi = HHV( lslop, 90 );
lswidth = lshi - lslo;
trend = 100*( lslop - lslo )/lswidth;

mawidth = MA( width, 100 );
relwidth = 100*(width - mawidth)/mawidth;

_N( tname = Name()+"("+FullName()+")" );

printf("Price and moving averages:\n");
printf( tname + " has closed " + WriteIf( C > movshort, "above" , "below" ) + " its Short time moving average. ");

printf("\nShort time moving average is currently " + WriteIf( movshort > movmed, "above", "below") + " mid-time, AND " + WriteIf( movshort > movlong, "above", "below" ) + " long time moving averages.");

printf("\nThe relationship between price and moving averages is: "+
WriteIf( C > movshort AND movshort > movmed, "bullish",
WriteIf( C < movshort AND movshort < movmed, "bearish", "neutral" ) ) + " in short-term, and "+
WriteIf( movshort > movmed AND movmed > movlong , "bullish",
WriteIf( movshort < movmed AND movmed < movlong, "bearish", "neutral" ) ) + " in mid-long term. ");

printf("\n\nBollinger Bands:\n");
printf(tname+ " has closed " +
WriteIf( C < bbot, "below the lower band by " +
WriteVal( 100 *( bbot-C )/ width, 1.1 ) + "%%. " +
WriteIf( trend < 30, " This combined with the steep downtrend can suggest that the downward trend in prices has a good chance of continuing. However, a short-term pull-back inside the bands is likely.",
WriteIf( trend > 30 AND trend < 70, "Although prices have broken the lower band and a downside breakout is possible, the most likely scenario for "+tname+" is to continue within current trading range.", "" ) ), "" ) +

WriteIf( C > btop, "above the upper band by " +
WriteVal( 100 *( C- btop )/ width, 1.1 ) + "%%. " +
WriteIf( trend > 70, " This combined with the steep uptrend suggests that the upward trend in prices has a good chance of continuing. However, a short-term pull-back inside the bands is likely.",
WriteIf( trend > 30 AND trend < 70, "Although prices have broken the upper band and a upside breakout is possible, the most likely scenario for "+tname+" is to continue within current trading range.", "" ) ), "" ) +

WriteIf( C < btop AND ( ( btop - C ) / width ) < 0.5,
"below upper band by " +
WriteVal( 100 *( btop - C )/ width, 1.1 ) + "%%. ",
WriteIf( C < btop AND C > bbot , "above bottom band by " +
WriteVal( 100 *( C - bbot )/ width, 1.1 ) + "%%. ", "" ) ));

printf("\n"+
WriteIf( ( trend > 30 AND trend < 70 AND ( C > btop OR C < bbot ) ) AND abs(relwidth) > 40,
"This picture becomes somewhat unclear due to the fact that Bollinger Bands are currently",
"Bollinger Bands are " )+
WriteVal( abs( relwidth ), 1.1 ) + "%% " +
WriteIf( relwidth > 0, "wider" , "narrower" ) +
" than normal.");

printf("\n");

printf(
WriteIf( abs( relwidth ) < 40, "The current width of the bands (alone) does not suggest anything conclusive about the future volatility or movement of prices.","")+
WriteIf( relwidth < -40, "The narrow width of the bands suggests low volatility as compared to " + tname + "'s normal range. Therefore, the probability of volatility increasing with a sharp price move has increased for the near-term. "+
"The bands have been in this narrow range for " + WriteVal(BarsSince(Cross(-40,relwidth)),1.0) + " bars. The probability of a significant price move increases the longer the bands remain in this narrow range." ,"")+
WriteIf( relwidth > 40, "The large width of the bands suggest high volatility as compared to " + tname + "'s normal range. Therefore, the probability of volatility decreasing and prices entering (or remaining in) a trading range has increased for the near-term. "+
"The bands have been in this wide range for " + WriteVal(BarsSince(Cross(relwidth,40)),1.0) + " bars.The probability of prices consolidating into a less volatile trading range increases the longer the bands remain in this wide range." ,""));

printf("\n\nThis commentary is not a recommendation to buy or sell. Use at your own risk.");
}
_SECTION_END();

_SECTION_BEGIN("MA1");
P = ParamField("Price field",-1);
Periods = Param("Periods", 15, 2, 300, 1, 10 );
Plot( MA( P, Periods ), _DEFAULT_NAME(), ParamColor( "Color", colorCycle ), ParamStyle("Style") );
_SECTION_END();

_SECTION_BEGIN("MA2");
P = ParamField("Price field",-1);
Periods = Param("Periods", 15, 2, 300, 1, 10 );
Plot( MA( P, Periods ), _DEFAULT_NAME(), ParamColor( "Color", colorCycle ), ParamStyle("Style") );
_SECTION_END();

_SECTION_BEGIN("MA3");
P = ParamField("Price field",-1);
Periods = Param("Periods", 15, 2, 300, 1, 10 );
Plot( MA( P, Periods ), _DEFAULT_NAME(), ParamColor( "Color", colorCycle ), ParamStyle("Style") );
_SECTION_END();