JS a+b=c

<script>

function add(){

var a,b,c;

a=Number(document.getElementById("first").value);

b=Number(document.getElementById("second").value);

c= a + b;

document.getElementById("answer").value= c;

}

</script>

Enter the First number : <input id="first" /><br />

Enter the Second number: <input id="second" /><br />

<button onclick="add()">Add</button>

<input id="answer" />

Enter the First number :
Enter the Second number: