I am using this amazing javascript to check if all my fields are filled in, but instead of a alert box I want to show a message on my page.

$(document).ready(function() {

$('form').submit(function() {

    var incomplete = $('form :input').filter(function() {

                         return $(this).val() == '';

                     });

    //if incomplete contains any elements, the form has not been filled 

    if(incomplete.length) {

        alert('Vul alle velden in en probeer het nog eens');

        //to prevent submission of the form

        return false;

    }

 });

 });

I tried to play with echo messages but it didn't work.