I want to be able to center the div 'testDiv' inside the parent div 'testContainer' (which has a height of 400, but for the sake of simplification I just wrote 400 in as a constant. I'm very new to javascript so I have little idea of what I'm doing wrong.

CSS:
Code:
body {
	overflow-x: hidden;
	background-color: #ededed;
}
#testContainer {
	height: 400px;
	width: 1100px;
	background-color:
...