Image gets 'clicked' when page loads without any action

snippet.js

<script>
// starts to use what we got stored
	var obj = getCookie();

//img swap snippet below
  var img = document.querySelectorAll("img.elIMG")[1];
  var img_href = document.querySelectorAll("img.elIMG")[1].dataset.imagelink;
// Starts to generate new img url based on cookie data
  var new_img_href = img_href.replace(/#prod_geo#/g,obj.prod_geo).replace(/#prod_name#/g,obj.prod_name).replace(/#subprod_name#/g,obj.subprod_name).replace(/#offer_name#/g,obj.offer_name).replace(/#offer_device#/g,obj.offer_device);
// Add listener on image. Swap parameters on the image url query string if it is clicked!
 function ChangeImg()
 {
   $(img).attr("data-imagelink",new_img_href);
 }
 img.addEventListener('click', ChangeImg(), false);

// button swap snippet below
 	var button = document.querySelectorAll("a.elButton");
 	var my_btn = button[0];
   href = my_btn.href;
 // Starts to generate new button url based on cookie data
 	href = href.replace(/#prod_geo#/g,obj.prod_geo).replace(/#prod_name#/g,obj.prod_name).replace(/#subprod_name#/g,obj.subprod_name).replace(/#offer_name#/g,obj.offer_name).replace(/#offer_device#/g,obj.offer_device);
 // Add listener on button. Swap parameters on the button url query string if it is clicked!
   function ChangeUrl()
   {
     $(my_btn).attr("href",href);
   }
   my_btn.addEventListener('click', ChangeUrl(), false);
</script>

updated_snippet.js

<script>
// starts to use what we got stored
	var obj = getCookie();

//img swap snippet below
  var img = document.querySelectorAll("img.elIMG")[1];
  var img_href = document.querySelectorAll("img.elIMG")[1].dataset.imagelink;
// Starts to generate new img url based on cookie data
  var new_img_href = img_href.replace(/#prod_geo#/g,obj.prod_geo).replace(/#prod_name#/g,obj.prod_name).replace(/#subprod_name#/g,obj.subprod_name).replace(/#offer_name#/g,obj.offer_name).replace(/#offer_device#/g,obj.offer_device);
// Add listener on image. Swap parameters on the image url query string if it is clicked!
 function ChangeImg()
 {
   $(this).attr("data-imagelink",new_img_href);
 }
 img.addEventListener('click', ChangeImg);

// button swap snippet below
 	var button = document.querySelectorAll("a.elButton");
 	var my_btn = button[0];
   href = my_btn.href;
 // Starts to generate new button url based on cookie data
 	href = href.replace(/#prod_geo#/g,obj.prod_geo).replace(/#prod_name#/g,obj.prod_name).replace(/#subprod_name#/g,obj.subprod_name).replace(/#offer_name#/g,obj.offer_name).replace(/#offer_device#/g,obj.offer_device);
 // Add listener on button. Swap parameters on the button url query string if it is clicked!
   function ChangeUrl()
   {
     $(this).attr("href",href);
   }
   my_btn.addEventListener('click', ChangeUrl);
</script>