Be careful of using AccountEquity in your risk calculations, here's a better alternative.

usingAccountBalance.mq4

double EXT_RISK_DIV = 10;
double EXT_RISK_MINAMT = 50;
double riskAmt = MathMax( getCashBalance() / EXT_RISK_DIV, EXT_RISK_MINAMT );
// this function returns the actual cash balance of all positions if they were to close now
double getCashBalance() {
  return( AccountBalance() + getOpenPL() );
}
// this function will calculate the total profit/loss of all open positions if all stops are hit
double getOpenPL() {
  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 );
}
// this function returns the profit/loss of a position
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( ( stop - open ) * result );
  } else if ( type == OP_SELL ) {
    return( ( open - stop ) * result );
  }
  return ( 0 );
}