copy textbox text to clipboard by js

<script>
function copyToClipboard()
{
  var copyInput = document.createElement("input");
  copyInput.setAttribute("value", document.getElementById("copyCode").value);
  document.body.appendChild(copyInput);
  copyInput.select();
  document.execCommand("copy");
  document.body.removeChild(copyInput);
}
</script>
<div class="input-group input-group-sm">  
	<input class="form-control" id="copyCode" value="copy this" type="text">
	<div class="input-group-btn">
		<button class="btn btn-primary btn-sm" type="button" onclick="copyToClipboard();">Copy this code</button>
	</div>							
</div>