Numeric input validation

HTML

<label for="numbers">Enter Numbers (separate with a comma):</label>
<input type="text" name="numbers" id="numbers">
<span class="validation-message"></span>
<input type="button" name="btnbutton"  >

CSS

.invalid { border-color : red; }
.validation-message {color: red;}

JavaScript

$('#btnbutton').on('keyup change', function(event){
    var inputField = $(this);
    var validationMsg = inputField.next();
    var value = inputField.val();
    //any character except for numbers, comma, and space
    var invalid = value.match(/[^0-9,\s]+/g); 
    if(invalid){
        inputField.addClass('invalid');
        validationMsg.text('Enter a vlid number)')
    } else {
        inputField.removeClass('invalid');
        validationMsg.text('');
    }

    $('body').append('<div>'
                     + 'you typed: [' +  value + '] a number? ' 
                     +  matches 
                     +'</div>');
});