var form = document.getElementById('login');
setDefaultText(form.elements.username, ' email address:');
setDefaultText(form.elements.password, 'password:');
setDefaultText(form.elements.email, 'email address:');
form.onsubmit = validateForm;
 
function setDefaultText(field, text) {
    text = text || field.defaultText;
    if (field.value === '') {
        field.value = text;
        field.defaultText = text;
        addClass(field, 'faded');
    }
    field.onfocus = function () {
        removeDefaultText(this);
    };
    field.onblur = function () {
        setDefaultText(this);
    };
}
function removeDefaultText(field) {
    if (field.value === field.defaultText) {
        field.value = '';
        removeClass(field, 'faded');
    }
}
function validateForm () {
    var isValid = true;
    if (hasDefaultText(this.elements.username)) {
        isValid = false;
    }
    if (hasDefaultText(this.elements.password)) {
        isValid = false;
    }
	if (hasDefaultText(this.elements.email)) {
        isValid = false;
    }
    return isValid;
}
function hasDefaultText(field) {
    return (field.value === field.defaultText);
}
function hasClass(ele,cls) {
    return ele.className.match(new RegExp('(\\s|^)'+cls+'(\\s|$)'));
}
 
function addClass(ele,cls) {
    if (!this.hasClass(ele,cls)) ele.className += " "+cls;
}
 
function removeClass(ele,cls) {
    if (hasClass(ele,cls)) {
        var reg = new RegExp('(\\s|^)'+cls+'(\\s|$)');
        ele.className=ele.className.replace(reg,' ');
    }
}