Source for demo by Motyar. See also description.
doc=document; body = doc.body;body.style.textAlign='center';if(c=doc.getElementById('c')){body.removeChild(c)}body.innerHTML='<style> li:hover{text-decoration:line-through;}</style><input id="additem" style="margin-top:30px;font-size:30px;width:80%;border:1px solid #ddd;text-align:center;border-radius:5px;-moz-border-radius:5px;font-family:Arial, Helvetica,sans-serif;margin:5px auto 20px;padding:5px"><ol id="todolist" style="list-style:none;padding:0;text-align:center;font-family:Arial, Helvetica, sans-serif;"></ol>';var d = document.getElementById("todolist"); var x= document.getElementById("additem"); document.onkeyup = function(e){ if(e.keyCode == 13) {d.innerHTML+='<li style="line-height:32px;position:relative;font-size:40px;text-align:center;cursor:pointer;color:'+Math.round(0xffffff * Math.random()).toString(16)+';" onclick="document.getElementById(\'todolist\').removeChild(this);">'+x.value+'</li>'; x.value='';}};