<form id="myForm" action="form_action.asp">
  First name: <input type="text" name="fname" value="Bob"><br>
  Last name: <input type="text" name="lname" value="Smith"><br>
</form>

<button onclick="myFunction()">Submit</button>

<p id="demo"></p>

<script>
function myFunction() {
    var x = document.getElementById("myForm").elements[1].value;
    document.getElementById("demo").innerHTML = x;
}
</script>