How do I Remove the black borders?

Apologies for the noob question,

But how do I remove the black borders in my game? I changed the window size and the layout size but it still remains.

Here's a screenshot of my dilemma: http://imgur.com/L15kdLx

Thanks.

Read this tutorial :

https://www.scirra.com/tutorials/73/sup ... reen-sizes

You just need to make your layout size wider.