This function calculates the risk per trade

getRiskPerTrade.mq4

extern double EXT_RISK_MINAMT = 50; // minimal amount of money to risk per trade
extern int EXT_RISK_MULT = 15; // maximum number of consecutive losses needed to wipeout account

// calculates the amount of money to risk per trade
double getRiskAmount() {
	return( MathMax( EXT_RISK_MINAMT, ( AccountBalance() + getStopPL() ) / EXT_RISK_MULT ) );
}

// this function returns the profit/loss if the stop is hit
double profitAtStop( string sym, double open, double stop, double lots, int type ) {    
    double result = lots * MarketInfo( sym, MODE_TICKVALUE ) / MarketInfo( sym, MODE_TICKSIZE );
    if ( type == OP_BUY ) {
        return( N( ( stop - open ) * result, 2 ) );
    } else if ( type == OP_SELL ) {
        return( N( ( open - stop ) * result, 2 ) );
    }
    return ( 0 );
}
 
// this function will calculate the total profit/loss if all current trailing stops were hit
double getStopPL() {
  int tot = OrdersTotal();
	double result = 0;
	for( int i = tot; i > 0; i -= 1 ) {
		if ( OrderSelect( i, SELECT_BY_POS, MODE_TRADES) ) {
			result += profitAtStop( OrderSymbol(), OrderOpenPrice(), OrderStopLoss(), OrderLots(), OrderType() );		
		}
	}
	return( result );
}

// simply call the getRiskAmount() function in your script to get the dollar amount of portfolio at risk

Doesn't compile because function N is not defined.

if ( type == OP_BUY ) {
    return( N( ( stop - open ) * result, 2 ) );
} else if ( type == OP_SELL ) {
    return( N( ( open - stop ) * result, 2 ) );