Need to optimize if statement

I make a currency converter and as a result it turns out that the condition operators are almost identical, it would be better to somehow optimize through the ternary operator

var exchan=document.getElementById("exchan");
exchan.addEventListener("click",function(e){
        var numberOne=document.getElementById("numberOne").value;
        var numberTwo=document.getElementById("numberTwo");
        var sExchange;
        var currencyOne=document.getElementById("currencyOne").value;
        var currencyTwo=document.getElementById("currencyTwo").value;
        if(currencyOne=="UAH" && currencyTwo=="USD"){
        numberTwo.value=(numberOne/cursUSD).toFixed(2);
        }
        if(currencyOne=="UAH" && currencyTwo=="EUR"){
        numberTwo.value=(numberOne/cursEUR).toFixed(2);
        }
        if(currencyOne=="UAH" && currencyTwo=="PLN"){
        numberTwo.value=(numberOne/cursPLN).toFixed(2);
        }

},false);