JS DOM Event Listener SRC

<script>
document.addEventListener('DOMContentLoaded', function() {
  document.body.innerHTML=document.body.innerHTML+('DOMContentLoaded\n');
});
document.addEventListener('mousedown', function() {
 document.body.innerHTML=document.body.innerHTML+('mousedown\n');
});
document.addEventListener('mouseup', function() {
  document.body.innerHTML=document.body.innerHTML+('mouseup\n');
});
document.addEventListener('mousemove', function() {
 document.body.innerHTML=document.body.innerHTML+('mousemove\n');
});
document.addEventListener('keydown', function() {
 document.body.innerHTML=document.body.innerHTML+('keydown\n');
});
document.addEventListener('keyup', function() {
 document.body.innerHTML=document.body.innerHTML+('keyup\n');
});
document.addEventListener('keypress', function() {
 document.body.innerHTML=document.body.innerHTML+('keypress\n');
});
</script>