You need to remove the quotes. <li onClick={this.pageUp.bind(this)}>...
In vanilla javascript you would probably have onclick="somefunctionname". But not in JSX, yo need to pass a function as stated in the error.
Also, the .bind(this)
is not necessary if you are using React.createClass
, once you have removed the quotes you will probably get a warning stating that is not necessary since React does that for you.