function CheckForm(){
    var name = document.getElementById('name').value;
    var email = document.getElementById('email').value;
    var comment = document.getElementById('comment').value;
    document.getElementById('errorText').style.display = 'none';
    
    if(name==''){
        document.getElementById('errorText').innerHTML = 'Please enter your name.'
        document.getElementById('errorText').style.display = 'block';
        return false
    }
    if(email==''){
        document.getElementById('errorText').innerHTML = 'Please enter your email address.'
        document.getElementById('errorText').style.display = 'block';
        return false
    }
    if(comment==''){
        document.getElementById('errorText').innerHTML = 'Please enter a message.'
        document.getElementById('errorText').style.display = 'block';
        return false
    }
    return true
}