How can I set a css border on one side only?

Question

For a given div I would like to only display a border on the left, right, top, or bottom side.

Currently I have the following, which puts a border on all s

Answer 1

You can specify border separately for all borders, for example:

#testdiv{
  border-left: 1px solid #000;
  border-right: 2px solid #FF0;
}

You can also specify the look of the border, and use separate style for the top, right, bottom and left borders. for example:

#testdiv{
  border: 1px #000;
  border-style: none solid none solid;
}