Trading at round numbers

I would like to make an EA that trades on round numbers for example at 1.4200. How do I tell metatrader to trade if the last 2 decimals are 00?

Edit: I think I just found the answer

double buy=MathRound(Ask*100);
double trade=buy/100;

if (Ask==trade && OrdersTotal()==0)
{
OrderSend(Symbol),OP_BUY,0.01,Ask,5,100,100);
}