Click to copy text from an input field, from a loop

Using Toolset, displaying a View with a loop.

HTML example:
<input type="text" value="[types field='code'][/types]" id="DiscountCode-[types field='promotion-id' output='raw'][/types]">
	<button onclick="myFunction('DiscountCode-[types field='promotion-id' output='raw'][/types]')">Copy text</button>

JS:

function myFunction(textid) {
  /* Get the text field */
  var copyText = document.getElementById(textid);

  /* Select the text field */
  copyText.select();

  /* Copy the text inside the text field */
  document.execCommand("copy");

  /* Alert the copied text */
  alert("Copied the text: " + copyText.value);
}