}
function calc()
{
var x = parseInt(document.getElementById("x").value);
var y = parseInt(document.getElementById("y").value);
var op = document.getElementById("op").innerText;

var z = "";
switch(op)
{
  case '+':
    z = x + y;
    break;
  case '-':
    z = x - y;
    break;
  case '*': ;
    z = x * y;
    break;
  case '/': ;
    z = x / y;
    break;
  default:
    z = '';
}
console.log(x,op,y,'=',z);
document.getElementById("z").innerText = z;

}