Change backgound color of input text after submit successfully

I want to change background of name and mail text input to yellow (default: white), content of button is "Sent". And deactivate the button. All of them are in a form. I write in JSP and want to change background by CSS.

<form action="/FashionBlog/ContactController" class="blockForm">
                    <!--display name and mail--> 
                    <div class="mainForm">
                        <div id="nameAndMail">
                            <div id="name">
                                <input id="myName" class="fontArial inputText" type="text" name="txtName" value="${name}" placeholder="Write name here"/>
                            </div>
                            &nbsp;&nbsp;
                            <div id="mail">
                                <input class="fontArial inputText" type="text" name="txtMail" value="${mail}" placeholder="Write mail here"/>
                            </div>
                        </div>
                        <!--display text are of message-->
                        <div id="meassageArea">
                            <textarea class="areaText fontArial" name="txtArea" placeholder="Write message here">${mess}</textarea>
                        </div>
                        <!--display button confirm send--> 
                        <div id="btnSend">
                            <input class="fontArial btnSendRadius" type="submit" value="Send - Click here"/>
                        </div>
                    </div>
                </form>