dynamic lot size

pls does anybody know how to set the lot size for this code so that it increases as the balance increase.

Thanks In Advance!

This Is The Code

//+------------------------------------------------------------------+
//| EMA_CROSS. mq4 |
//| Coders Guru |
//| https://www.forex-tsd.com |
//+------------------------------------------------------------------+
//+------------------------------------------------------------------+
//| TODO: Add Money Management routine |
//+------------------------------------------------------------------+

#property copyright "Coders Guru"
#property link "https://www.forex-tsd.com"
//---- input parameters
extern double TakeProfit = 1000;
extern double StopLoss = 30;
extern double Lots = 0.1;
extern double TrailingStop = 10;
extern int ShortEma = 1;
extern int LongEma = 2;
//+------------------------------------------------------------------+
//| expert initialization function |
//+------------------------------------------------------------------+
int init()
{
//----
return(0);
}
//+------------------------------------------------------------------+
//| expert deinitialization function |
//+------------------------------------------------------------------+
int deinit()
{
//----
return(0);
}
//+------------------------------------------------------------------+
//| |
//+------------------------------------------------------------------+
int Crossed (double line1 , double line2)
{
static int last_direction = 0;
static int current_direction = 0;
//Don't work in the first load, wait for the first cross!
static bool first_time = true;
if(first_time == true)
{
first_time = false;
return (0);
}
//----
if(line1 > line2)
current_direction = 1; //up
if(line1 < line2)
current_direction = 2; //down
//----
if(current_direction != last_direction) //changed
{
last_direction = current_direction;
return(last_direction);
}
else
{
return (0); //not changed
}
}
//+------------------------------------------------------------------+
//| expert start function |
//+------------------------------------------------------------------+
int start()
{
int cnt, ticket, total;
double SEma, LEma;
//----
if(Bars < 100)
{
Print("bars less than 100");
return(0);
}
//----
if(TakeProfit < 10)
{
Print("TakeProfit less than 10");
return(0); // check TakeProfit
}
//----
SEma = iMA(NULL, 0, ShortEma, 0, MODE_EMA, PRICE_CLOSE, 0);
LEma = iMA(NULL, 0, LongEma, 0, MODE_EMA, PRICE_CLOSE, 0);
//----
static int isCrossed = 0;
isCrossed = Crossed (LEma, SEma);
//----
total = OrdersTotal();
if(total < 1)
{
if(isCrossed == 1)
{
ticket = OrderSend(Symbol(), OP_BUY, Lots, Ask, 3, Ask - StopLoss*Point,
Ask + TakeProfit*Point, "EMA_CROSS", 12345, 0, Green);
if(ticket > 0)
{
if(OrderSelect(ticket, SELECT_BY_TICKET, MODE_TRADES))
Print("BUY order opened : ", OrderOpenPrice());
}
else
Print("Error opening BUY order : ", GetLastError());
return(0);
}
if(isCrossed == 2)
{
ticket = OrderSend(Symbol(), OP_SELL, Lots, Bid, 3, Bid + StopLoss*Point,
Bid - TakeProfit*Point, "EMA_CROSS", 12345, 0, Red);
if(ticket > 0)
{
if(OrderSelect(ticket, SELECT_BY_TICKET, MODE_TRADES))
Print("SELL order opened : ", OrderOpenPrice());
}
else
Print("Error opening SELL order : ", GetLastError());
return(0);
}
return(0);
}
//----
for(cnt = 0; cnt < total; cnt++)
{
OrderSelect(cnt, SELECT_BY_POS, MODE_TRADES);
if(OrderType() <= OP_SELL && OrderSymbol() == Symbol())
{
if(OrderType() == OP_BUY) // long position is opened
{
// check for trailing stop
if(TrailingStop > 0)
{
if(Bid - OrderOpenPrice() > Point*TrailingStop)
{
if(OrderStopLoss() < Bid - Point*TrailingStop)
{
OrderModify(OrderTicket(), OrderOpenPrice(),
Bid - Point*TrailingStop,
OrderTakeProfit(), 0, Green);
return(0);
}
}
}
}
else // go to short position
{
// check for trailing stop
if(TrailingStop > 0)
{
if((OrderOpenPrice() - Ask) > (Point*TrailingStop))
{
if((OrderStopLoss() > (Ask + Point*TrailingStop)) ||
(OrderStopLoss() == 0))
{
OrderModify(OrderTicket(), OrderOpenPrice(),
Ask + Point*TrailingStop,
OrderTakeProfit(), 0, Red);
return(0);
}
}
}
}
}
}
//----
return(0);
}
//+------------------------------------------------------------------+