Help me in coding in amitrader

My requirement is simple Order: Buy nifty future if nifty future trades below 8600 (it may be 8599,8598.… .8590 ) Close buy position if nifty trades above 8600…

your condition is not clear, for placing entry and target you can also do with normal order type

For the above query you can check below Price Break AFL as example


Title = Name()+ " Price Break Indicator." ;
//+ "  Trend is " + Trend_Text + ".  SEQUENCE IS " + Sequence_Text;

/////////   Parameters  ////////

nBars_To_Scan = Param("Number of bars to Scan",20, 10,480, 10);		//Number of bars to include in scan
PB_Interval = Param("Number of Bars for Price Break",3,2,3,1);

/////////  Use Array of Prices and Price Breaks to Look Back and Determine What Price Break is For Current Bar
Seedbar = nBars_To_Scan + 1;					//Need an initial value to start the PB process
if (BarCount > Seedbar) 						//Make sure there are enough bars available to evaluate
Price[0]= LastValue(Ref(C,-Seedbar));			//Seed the 0 Bar in the Array with Values
Trend[0]=1;										//1 = Long, 0=Short
Sequence[0]=0;									//Sequence counter - counts number of new price breaks
Price_Break[0] = LastValue(Ref(C,-Seedbar));
High_C1[0] = LastValue(Ref(C,-Seedbar));		//Highest Close 1 Ago
High_C2[0]= LastValue(Ref(C,-Seedbar));			//Highest Close 2 Ago
High_C3[0]= LastValue(Ref(C,-Seedbar));			//Highest Close 3 Ago
Low_C1[0] = LastValue(Ref(C,-Seedbar));			//Lowest Close 1 Ago
Low_C2[0] = LastValue(Ref(C,-Seedbar));			//Lowest Close 2 Ago
Low_C3[0] = LastValue(Ref(C,-Seedbar));			//Lowest Close 3 Ago
for ( i=1; i < Seedbar ; i++) 			//Cycle through prices filling in price array and caculating price breaks 
	Prior = i-1;									//Index for Prior entry in array.  Set the current array values to 
	Trend[i]=Trend[Prior];						//prior values to make sure everything that isn't changed later
	Price_Break[i] = Price_Break[Prior];			//gets carried forward to the next row in the array.
			Low_C1[i] = Low_C1[Prior]; 			//Carryover current values
			Low_C2[i] = Low_C2[Prior];
			Low_C3[i] = Low_C3[Prior];  
			High_C1[i] = High_C1[Prior];			//Carryover current values
			High_C2[i] = High_C2[Prior];
			High_C3[i] = High_C3[Prior];
			Sequence[i] = Sequence[Prior];

	Price[i] = LastValue (Ref (C,-(Seedbar-i)));	//Seedbar is the bar just in front of where I start the method.  Works since i starts at 1

	if (Price[i] >Price[Prior] AND Trend[Prior] == 1 )	// If Close is Greater than the prior close And the Trend is Long
	{		if (Price[i] >High_C1[Prior])			//If the Close is greater than the last highest close
			{									//Test For Price Break.  The IIF is there to accomodate a 2 price or 3 price break option
												//based on the PB_Interval parameter
			Price_Break[i] = IIf(PB_Interval == 3,High_C3[Prior],IIf(PB_Interval == 2,High_C2[Prior],High_C3[Prior]));	
												//The 3PB method says I take the highest close 4 ago as the new price break.
			Sequence[i] = Sequence[i] + 1;		//Increment Sequence if Price Break
			High_C3[i] = High_C2[Prior];			//Stacking the higher closes like this avoids having to go back and iterate through the.
			High_C2[i] = High_C1[Prior];			//closes to find and count the higher closes.  They are just carried forward in the stack.
			High_C1[i] = Price[i];				//When a higher close occurs, it is put on the top of the stack, each close below is
			}									//pushed down in sequence, and the earliest (farthest back) close goes away.

	if (Price[i] >Price[Prior] AND Trend[Prior] == 0 )	// If Close is Greater than the prior close And the Trend is Short
	{		if (Price[i] >Price_Break[Prior])		//If Close > Price Break in trend is Short, Reverse and go Long
			High_C1[i] = High_C2[i] = High_C3[i] = Price[i];				//Initialize sequence of new Highs
			Price_Break[i] = Price[i];				//Set new value for Price Break
			Trend[i] = 1;							//Set the trend Long
			Sequence = 0;

	if (Price[i] <Price[Prior] AND Trend[Prior] ==0)	// If The Close is less than the prior close And the Trend is Short
	{		if (Price[i] <Low_C1[Prior])			//If the Close is less than the last lowest close
			Price_Break[i] = IIf(PB_Interval == 3,Low_C3[Prior],IIf(PB_Interval == 2,Low_C2[Prior],Low_C3[Prior]));	//Test For Price Break
			Sequence[i] = Sequence[i] + 1;		//Increment Sequence if Price Break
			Low_C3[i] = Low_C2[Prior];			//Update sequence of new Lows
			Low_C2[i] = Low_C1[Prior];
			Low_C1[i] = Price [i];

	if (Price[i] <Price[Prior] AND Trend[Prior] ==1)	// If The Close is less than the prior close And the Trend is Long
	{		if (Price[i] < Price_Break[Prior])				//If Close < Price Break in Long Trend, reverse and go Short
			Low_C1[i] = Low_C2[i] = Low_C3[i] = Price[i];	//Initialize sequence of new Lows
			Price_Break[i] = Price[i];							//Set new value for Price Break
			Trend[i] = 0;								//Set Trend Short
			Sequence = 0;

////  Plot the Price Breaks.
Bar_x1=BarCount - (nBars_To_Scan - Prior );
Bar_x2=BarCount - ( nBars_To_Scan - i);
PB_Color = IIf(Trend[i] == 1,colorGreen, colorRed);
Sequence_Text = NumToStr(Sequence,format=1.0);
Trend_Text = WriteIf(Trend[i] > 0, "Long","Short");

}												//Close the For Loop

}												//Close the first test for sufficient bars to do the study