JSFiddle - React, Tailwind, and code Playground

HTML

<body>
    <div class="header">
        <img src="images/headerbefore.jpg" />
    </div>
    <form action="vote.php" method="post" class="formClass" name="buttonForm">
        <table class="sixButtons">
            <tr>
                <td>
                    <button type="image" onclick="setavalue(1)" enctype="multipart/form-data" id="votingvalue1" class="button1">
                    </td>
                <td>
                    <button type="image" onclick="setavalue(2)" enctype="multipart/form-data" id="votingvalue2" class="button2">
                </td>
            </tr>
            <tr>
                <td>
                    <button type="image" onclick="setavalue(3)" enctype="multipart/form-data" id="votingvalue3" class="button3">
                </td>
                <td>
                    <button type="image" onclick="setavalue(4)" enctype="multipart/form-data" id="votingvalue4" class="button4">
                </td>
            </tr>
            <tr>
                <td>
                    <button type="image" onclick="setavalue(5)" enctype="multipart/form-data" id="votingvalue5" class="button5">
                </td>
                <td>
                    <button type="image" onclick="setavalue(6)" enctype="multipart/form-data" id="votingvalue6" class="button6">
                </td>
            </tr>
        </table>
        <input id="votingvalue" type="hidden" value="" name="votingvalue">
        <input type="hidden" value="2" name="voteid">
    </form>
    </div>
</body>

</html>

CSS

body,
html {   
    font-family: "HelveticaNeue-Bold",  sans-serif ;
    background-color: black;  
    max-width:480px;
    max-height:640px;
    margin-left: auto ;
    margin-right: auto ;
}

#container{
width: 100%;
height: 100%;
}

.button1 {

    background:url(http://thumb4.ftd.de/standardteaser/Image/2012/11/19/20121119200026.1845.maerskline.290x180.jpg) no-repeat center center;

    background-size: 100%;

    width:100%;

    max-width: 100%;

    height:100%;

    cursor:pointer;

    border:none;

    font-size: 0.1px;

}

.button2 {

    background:url(http://thumb4.ftd.de/standardteaser/Image/2012/11/19/20121119200026.1845.maerskline.290x180.jpg) no-repeat center center;

    background-size: 100%;

    width:100%;

    height:100%;

    cursor:pointer;

    max-width: 100%;

    border:none;

    font-size: 0.1px;

}

.button3 {

    background:url(http://thumb4.ftd.de/standardteaser/Image/2012/11/19/20121119200026.1845.maerskline.290x180.jpg) no-repeat center center;

    background-size: 100%;

    width:100%;

    height:100%;

    max-width: 100%;

    cursor:pointer;

    border:none;

    font-size: 0.1px;

}

.button4 {

    background:url(http://thumb4.ftd.de/standardteaser/Image/2012/11/19/20121119200026.1845.maerskline.290x180.jpg) no-repeat center center;

    background-size: 100%;

    width:100%;

    height:100%;

    max-width: 100%;

    cursor:pointer;

    border:none;

    font-size: 0.1px;

}

.button5 {

    background:url(http://thumb4.ftd.de/standardteaser/Image/2012/11/19/20121119200026.1845.maerskline.290x180.jpg) no-repeat center center;

    background-size: 100%;

    width:100%;

    max-width: 100%;

    height:100%;

    cursor:pointer;

    border:none;

    font-size: 0.1px;

}

.button6 {

    background:url(http://thumb4.ftd.de/standardteaser/Image/2012/11/19/20121119200026.1845.maerskline.290x180.jpg) no-repeat center center;

    background-size: 100%;

    width:100%;

    max-width: 100%;

    height:100%;

 ...

JavaScript

function setavalue(value) {
    value = parseInt(value);
    if (value === 1) {
        document.getElementById('votingvalue').value = '1';
    } else if (value === 2) {
        document.getElementById('votingvalue').value = '2';
    } else if (value === 3) {
        document.getElementById('votingvalue').value = '3';
    } else if (value === 4) {
        document.getElementById('votingvalue').value = '4';
    } else if (value === 5) {
        document.getElementById('votingvalue').value = '5';
    } else if (value === 6) {
        document.getElementById('votingvalue').value = '6';
    }
    document.forms["buttonForm"].submit();
}