Untitled

<!DOCTYPE html>
<html>
<head>
<style>
.button {
  display: inline-block;
  padding: 15px 25px;
  font-size: 24px;
  cursor: pointer;
  text-align: center;
  text-decoration: none;
  outline: none;
  color: #fff;
  background-color: #7aa2e2;
  border: none;
  border-radius: 10px;
  box-shadow: 0 9px #777;
}

.button:hover {background-color: #5a83c4}

.button:active {
  background-color: #a5442e;
  box-shadow: 0 5px #555;
  transform: translateY(4px);
}
</style>
</head>
<body>
<button class="button" type="button" value=1 onclick="pressed(1)">1</button>
<button class="button" type="button" value=2 onclick="pressed(2)">2</button>
 <p id="lcd"></p>
 <script>
 var listOper = ["+","-","*","/","C"];
 var prevKey = "";
 var oper = "";
 function pressed(key){
    var lcd = document.getElementById("lcd");
    //lcd.innerHTML = key;
    if (key in listOper){
        oper = key;
    }
    }
 </script>
</body>
</html>