JSFiddle - React, Tailwind, and code Playground

HTML

<form action="submitPage.php" method="post" onsubmit="savePathInVar();"> 
  <table>
  <tr>
    <td><img src="http://placehold.it/350x150" onclick="changecolor(this);" /></td>
    <td><img src="http://placehold.it/350x150" onclick="changecolor(this);" /></td>
  </tr>
    <input value="ClickedImaged" id="hiddenImgLoc"/>
    <input type="submit" value="Submit" />          
  </table>
</form>

JavaScript

changecolor = function(img)
{
var images = document.getElementsByTagName("img");
for(var i=0,j=images.length; i<j; i++)
{
    images[i].style.borderColor="#000";
}
img.style.borderColor="#F00";
//Operate on img location as before
savePathInVar(img.src);
}

function savePathInVar(ImgLocation)
{
   document.getElementById('hiddenImgLoc').value = ImgLocation
}