border:
a style sheet property ( STYLE tag), or a style property inside a tag (STYLE attribute). Specifies the appearance of a border around an object and between frames.
border: red 2mm double

1. border-color: none green select_color
2. border-width: thin medium thick 1px 1mm 1cm 1in 1pt 1pc
3. Border-style: none solid double groove ridge inset outset