<section>
	<h1>Type two numbers</h1>
  
  <select name="note" id="note-select-1">
    <option value="">--Please choose an option--</option>
    <option value ="1" >1</option>
    <option value ="2" >2</option>
  </select>
  <select name="note" id="note-select-2">
    <option value="">--Please choose an option--</option>
    <option value ="10" >10</option>
    <option value ="20" >20</option>
  </select>
	
	<button id="button" onclick="myFunction()">calculate</button>
	<p id="sum">The global note is </p>
 

function myFunction() {
  /* Get values of input elements */
	var a = document.getElementById('note-select-1').value;
	var b = document.getElementById('note-select-2').value;

	/* calculate sum, product and quotient of values */
	var sum = Number(a) + Number(b);
	
  /*Output results*/
	document.getElementById("sum").innerHTML = "The global note is : " + sum;
 
		
}