How to stretch the background image to fill a div

I want to set a background image to different divs, but my problems are:

1. The size of image is fixed(60px).
2. Varying div's size

How can I stretch the background-image to fill the whole background of the div?

#div2{
  background-image:url(http://s7.static.hootsuite.com/3-0-48/images/themes/classic/streams/message-gradient.png);
  height:180px;
  width:200px;
  border: 1px solid red;
}

Check the code here.

Add

background-size:100% 100%;

to your css underneath background-image.

You can also specify exact dimensions, i.e.:

background-size: 30px 40px;

Here: JSFiddle

You can use:

background-size: cover;

Or just use a big background image with:

background: url('../images/teaser.jpg') no-repeat center #eee;