function loginHandler() {
    var classwareMessage = getQueryString('classwareMessage');
    if(classwareMessage != '')
        switch(classwareMessage.toLowerCase()) {
            case 'loginfail':
                alert('Your username and password were not accepted.\n' +
                      'Please try again. If you need help, please visit our Support section.');
                break;
            case 'forgotpass':
                alert('A password reset confirmation message has been sent to your registered e-mail address.\n' +
                      'If you need additional help, please visit our Support section.');
                break;
            case 'forgotpassfail':
                alert('The e-mail address you provided is not valid for a password reset.\n' +
                      'Please try again. If you need help, please visit our Support section.');
                break;
            case 'nobook':
                alert('You do not have access to any books.\n' +
                      'If you need additional help, please visit our Support section.');
                break;
            default:
                alert('Classware message: ' + classwareMessage);
                break;
        }
    
    if(document.getElementById('formUsername')) {
        /*document.getElementById('formUsername').focus();*/
        
        if(getQueryString('focusLogin') != '') {
            document.getElementById('formUsername').value = 'login here ...';
            document.getElementById('formUsername').select();
        }
    }
}

function validateLogin(formObject) {
    if(formObject.username.value == '' || formObject.username.value == 'login here ...') {
        alert('Please enter your username before signing in.');
        document.getElementById('formUsername').focus();
    }
    else if(formObject.password.value == '') {
        alert('Please enter your password before signing in.');
        document.getElementById('formPassword').focus();
    }
    else return true;
    
    return false;
}

if(window.addEventListener)  window.addEventListener('load', loginHandler, false);   // for good browsers
else if(window.attachEvent)  window.attachEvent('onload', loginHandler);             // for IE