Javascript Form How to - Validate form submit value

Question

We would like to know how to validate form submit value.

Answer


<!DOCTYPE html>
<html>
<head>
<script type='text/javascript'>
window.onload=function(){<!--from  w w  w.j  a v  a 2s  .  co m-->
    var idImp = document.getElementById("id_importeur");
    document.getElementById('button').onclick = function(){
        listUsers(document.getElementById('input').value);
    };
    function listUsers(profil) {
        switch (profil.toUpperCase()) {
            case "DGA":
                idImp.innerHTML = "DGA";
                break;
            case "INDUSTRIEL":
                idImp.innerHTML = "INDUS";
                break;
            default:
                idImp.innerHTML = "Error";
                break;
        }
    }
}
</script>
</head>
<body>
  <div id="id_importeur">Result</div>
  <input type="text" id="input" />
  <input id="button" type="button" value="Submit" />
</body>
</html>

The code above is rendered as follows: