Hide image if another one is opened, vice versa

I’m have code for 2 images (Image1, Image2) that both open if 2 other images are clicked, with onclick and a java part at the end, like so:

<table style="whatever">
    <tbody>
        <tr style="whatever"">

            <td><a href="link to game1 when the image is clicked" alt="Game1" target="blank" onclick="AfficherCacher('Image1')"> <img src="the image clicked to open Game1+Image1.jpg" width="1689" height="955" class="img-fluid atto_image_button_text-bottom"></a><br></td>
           <td><a href="link to game2 when the image is clicked" alt="Game2" target="blank" onclick="AfficherCacher('Image2')"> <img src="the image clicked to open Game2+Image2.jpg" width="1689" height="955" class="img-fluid atto_image_button_text-bottom"></a><br></td>
        </tr>
    </tbody>
</table>

then

</table>
   <table style="whatever">
    <tbody>
        <tr style="whatever">
            <td>
                <div id="Image1">
                    <ul>
                        <img src="Image1.jpg">
                    </ul>
                </div>
            </td>
</table>
   <table style="whatever">
    <tbody>
        <tr style="whatever">
            <td>
                <div id="Image2">
                    <ul>
                        <img src="Image2.jpg">
                    </ul>
                </div>
            </td>

And then the JavaScript part at the end making it all work:

<p>
    <script type="text/javascript">
        // <![CDATA[
        function AfficherCacher(texte) {
            var test = document.getElementById(texte).style.display;
            if (test == "block") {
                document.getElementById(texte).style.display = "none";
            } else {
                document.getElementById(texte).style.display = "block";
            }
        }
        // ]]>
    </script>
</p>

The only thing is that both Image1 and Image2 can be displayed on the page at the same time, which i DO NOT want. I would like for opening Image2 to make Image1 disapear, and for opening Image1 to make Image2 disapear.

I do not know what to use for this.

Thank you in advance for your help.

I have tried inventing “if” conditions, but I am not JavaScript (or CSS) litterate, so I’m going in blind and I’m clearly doing something wrong. I don’t know what I’m able to use and what exists/works.