A CSS border value for the outer boundary of the weblet. For example '1px dashed red'.
Default value
Blank (no border is shown).
Valid values
Any valid CSS border string. This consists of a width, a style and a color, each separated by a space. Properties can be omitted from this list but must be in this order. For example, "solid #ff0000" is valid. For more information on the CSS border property, look at the W3C specification.