function isValidEmail(email){
    if (/^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/.test(email)) return true;
    return false;
}

    $(function(){
        $('#qform').submit(function(){
            var obj = $('#name');
            var val = obj.val();
            if (!val){
                alert('Please input Your Name!');
                obj.focus();
                return false;
            }
            obj = $('#phone');
            val = obj.val();
            if (!val){
                alert('Please input Your Phone!');
                obj.focus();
                return false;
            }
            obj = $('#email');
            val = obj.val();
            if (!val || !isValidEmail(val)){
                alert('Please input Your valid E-mail!');
                obj.focus();
                return false;
            }
            return true;
        });
    });