var email = document.getElementById("email");
var message = document.getElementById("message");
var keystring = document.getElementById("keystring");
var submit = document.getElementById("submit");
var select = document.getElementById("subject");
var bSelect = false;

submit.disabled = true;

email.onchange = checkForm;
email.onkeyup = checkForm;
email.onblur = checkForm;

select.onchange = checkForm;

message.onchange = checkForm;
message.onkeyup = checkForm;
message.onblur = checkForm;

keystring.onchange = checkForm;
keystring.onkeyup = checkForm;
keystring.onblur = checkForm;

function checkForm(){
	if((keystring.value.length > 1) && (message.value != '') && (select.value != 0) && checkEmail(email.value)){
		submit.disabled = false;
	} else {
		submit.disabled = true;
	}
}



function checkEmail(val){
	var email = /^\w+([.-]?\w+)+@\w+([.-]?\w+)*\.[a-z]{2,4}$/;
	var result = val.match(email);
	if(result != null){
		return true;
	} else {
		return false;
	}
}