Append value to an input field in Javascript

Question

Here i'm trying to append some text to an input field but everytime the old value gets replaced with new value.

HTML

Javascript

function update(i){
 document.getElementById('taginput').value = i.innerHTML;
  }

no jquery please.

user_16059041 · Answer

document.getElementById('my_msg').value = "text-value";

Use above script to append 'text-value' to input field.

Thanks