var $ = function (id) {
    return document.getElementById(id);
}
var stateCodeLookup = function (stateCode) {
	var states = ["CA", "WA", "OR", "NV", "NM", "AZ", "WY", "MT", "TX","FL"];
	stateCode = stateCode.toUpperCase();
	for (var i = 0; i < states.length; i++) {
		if (states[i] == stateCode) {
			return true;
		} 
	}
	return false;
}
var joinList = function () {
	var emailAddress1 = $("email_address1").value;
	var emailAddress2 = $("email_address2").value;
	var isValid = true;
	
	// validate the first email address
	if (emailAddress1 == "") { 
		$("email_address1_error").firstChild.nodeValue = "This field is required.";
		isValid = false;
	} else {
		$("email_address1_error").firstChild.nodeValue = "";
	} 
	
	// validate the second email address
	if (emailAddress2 == "") { 
		$("email_address2_error").firstChild.nodeValue = "This field is required.";
		isValid = false; 
	} else if (emailAddress1 !== emailAddress2) { 
		$("email_address2_error").firstChild.nodeValue = "This entry must equal first entry.";
		isValid = false;
	} else {
		$("email_address2_error").firstChild.nodeValue = "";
	}
	
	// validate the first name entry  
	if ($("first_name").value == "") {
		$("first_name_error").firstChild.nodeValue = "This field is required.";
		isValid = false;
	} 
	else {
		$("first_name_error").firstChild.nodeValue = "";
	}
	
	// validate the state code entry
	var stateCode = $("state_code").value;
	if (!stateCodeLookup(stateCode)) {
		$("state_code_error").firstChild.nodeValue = "State code is invalid.";
		isValid = false;
	} 
	else {
		$("state_code_error").firstChild.nodeValue = "";
	}
	
	// submit the form if all entries are valid
	if (isValid) {
		$("email_form").submit(); 
	}
}
window.onload = function () {
    $("join_list").onclick = joinList;
    $("email_address1").focus();
}