function calculatedesktopoffset(length) {
  return '-' + (length / 2) * math.tan(15 * math.pi / 180) + 'px';
}
function makeovaloverlay() {
  var section01 = document.getelementbyid("section01");
  var bannertext = section01.getelementsbyclassname('bannertext')[0];
  var bannerimage = section01.getelementsbyclassname('bannerimage')[0];
  var oval = section01.getelementsbyclassname('oval')[0];
  var $height = bannertext.clientheight;
  var $width = bannertext.clientwidth;
  
  if (window.innerwidth < 992) {
    bannerimage.style.height = $width + 'px';
    oval.style.width = $width * 2.87 + 'px';        // oval overlay needed to be 2.87x the width
    oval.style.height = $width * 2.87 + 'px';       // of the content, per design
    oval.style.right = '-' + $width * 0.76 + 'px';  // these are magic numbers, because i
    oval.style.top = '-' + $width * 0.2 + 'px';     // gave up trying to figure out the trig
  } else {
    oval.style.width = $height * 2 + 'px';  // oval overlay need to be 2x the height
    oval.style.height = $height * 2 + 'px'  // of the content, per design
    oval.style.top = "-50%"; 
    oval.style.right = calculatedesktopoffset($height); 
    bannerimage.style.height = 'auto';
  }
}

makeovaloverlay();
window.onresize = function() {
  makeovaloverlay()
};