How to use border image along one side only?

border-bottom-width: 1px;

Put it after your other border stuff to override a specific border side.

you could use short hand but i think this is easier for readability.

Change border-width:2px to border-width:0 0 2px

In this way you are actually setting border bottom width 2px and other sides width equal to zero

Demo http://jsfiddle.net/naveenksh/eqpt5/3/