function formCheck() {
	var form = document.getElementById('reply-form');
	
	if( form.title.value.length > 3 && form.author.value.length > 3 && form.msg.value.length > 3 )
		form.submit.disabled = false;
	else 
		form.submit.disabled = true;
	
	form.title.style.backgroundColor  = form.title.value.length  > 3 ? "#AFA":"#FAA"; 
	form.author.style.backgroundColor = form.author.value.length > 3 ? "#AFA":"#FAA";
	form.msg.style.backgroundColor    = form.msg.value.length    > 3 ? "#AFA":"#FAA";
}


function formLoad() {
	if( document.getElementById('reply-form') ) {
		document.getElementById('reply-form').addEventListener('keyup', formCheck, false);
		document.getElementById('reply-form').c.value += "Ok";
		formCheck();
	}
}

window.addEventListener('load',formLoad, false);