var loginHintInit;
var checkEmail;

checkEmail = function(src)
{
    var txEmail = src.all('email');
    var emailString = txEmail.value;
    if (isNullOrEmpty(emailString))
    {
        return 'Please input your email!\r\n';
    }
    else if (emailString.search(/^\w+([-+.'_]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*$/i)<0)
    {
        return 'Your email is invalid!\r\n';
    }
    else
    {
        return '';
    }
}

function messageBoardInit()
{

    onSubmitInit();
}

function onSubmitInit()
{
    var mainDoc = window.document;
    var form = mainDoc.forms['frmMessageBoard'];
    form.onsubmit = onSubmit;
}

function isNullOrEmpty(str)
{
    if (str == null || str.length==0)
    {
        return true;
    }
    else
    {
        return false;
    }
}

function onSubmit()
{
    var src = event.srcElement;
    if (src != null)
    {
        var result = checkTitle(src);
        result += checkContent(src);
        if (checkEmail) {result += checkEmail(src);}
        
        if (isNullOrEmpty(result))
        {              
            return true;
        }
        else
        {
            window.alert(result);
            return false;
        }
    }
    else
    {
        window.alert('目前站点暂时无法接收留言.');
        return false;
    }
}

function checkTitle(src)
{
    var txTitle = src.all('title');
    var titleString = txTitle.value;
    if (isNullOrEmpty(titleString))
    {
        return '请填写留言标题！\r\n';
    }
    else
    {
        return '';
    }
}

function checkContent(src)
{
    var txContent = src.all('content');
    var contentString = txContent.value;
    if (isNullOrEmpty(contentString))
    {
        return '请填写留言内容！\r\n'
    }
    else
    {
        return '';
    }
}

messageBoardInit();