From http://www.w3schools.com (Copyright Refsnes Data)
The width property specifies the content width of a box.
| Value | Description |
|---|---|
| auto | Default. The browser calculates the actual width |
| length | Specifies a fixed width in px, cm, etc. Negative values are not allowed |
| % | Defines the width in % of the parent element's width |
From http://www.w3schools.com (Copyright Refsnes Data)