Mousehover picture bigger

I want to make my picture bigger while holding down crtlKey while hovering over the picture and when I press crtl agean it supoused to go back. Soo i made that it would chooge all the pictures and then adds a eventlistener. The pictures goes bigger with chrome extenson but i dosen´t respond to Crtlkey response, not getting back to its original form.

    window.onload = function () {

   var srcList = $('img').map(function () {
    return this.src
  }).get() */
  var ctrlKey = String.fromCharCode(keyPress)
  // const ctrlKey = String.fromCharCode(event.buttonPress)
  var images = document.getElementsByTagName('img')
  // console.log(images)
  // var srcList = []
  // for (var i = 0; i < images.length; i++) {
  //  srcList.push(images[i].src)
  // }
  for (var i = 0; i < images.length; i++) {
    var img = images[i]
    img.addEventListener('mouseover', function (event) {
      // console.log(event)
      // if (!event.ctrlKey) { return }
      var el = event.target
      el.style.width = el.offsetWidth * 1.5 + 'px'
      el.style.height = el.offsetHeight * 1.5 + 'px'

      el.style.position = 'fixed'
      el.style.transition = '2s'
      // el.style.left = event.x + el.offsetWidth * 0.5 + 'px' 
      // el.style.top = event.y + el.offsetHeight * 0.5 + 'px'
      el.style.left = window.innerWidth / 2 - 0.5 * el.style.width.replace('px', '') + 'px'
      el.style.top = 0
      console.log(event)
    }, true)

    img.addEventListener('keydown', function (event) {
      const ctrlKey = String.fromCharCode(event.which)
      if (!event.ctrlKey) { return }

      console.log(event)
      var el = event.target
      el.style.width = el.offsetWidth / 3 * 2 + 'px'
      el.style.height = el.offsetHeight / 3 * 2 + 'px'

      el.style.position = 'relative'
      el.style.left = 0
      el.style.top = 0
    }, true)
  }
}

// Image.addEventListener(onmouseover, src('img')[, large]);

// var img = document.getElementById('image-hover')

mousehover, making picture bigger with Chrome extension

I wanna make chrome extension when you go to a page that when you hover any picture that the picture wold get bigger. I haven’t had lot of expeience yet with programming. What is the best way to get there and what is the best way to get that it wold work in any page?
I already have Manifest.json and what had to be done to get extension.

mosehover, making picture bigger with Chrome extension

I wanna make chrome extension when you go to a page that when you hover any picture that the picture wold get bigger. I haven´t had lot of expeience yet with programming. What is the best way to get there and what is the best way to get that it wold work in any page?
I already have Manifest.json and what had to be done to get extension.