<p>I have one autocomplete search, in which by typing few characters it will show all the names, which matches the entered character. I am populating this data in the jsp using DIV tag, by using mouse I'm able to select the names. But I want to select the names in the DIV tag to be selected using the keyboard up and down arrow. Can anyone please help me out from this.</p>

I assume that you have an input which handles the input.
map onkeyup-eventhandler for that input in which you read out event.keyCode, and do stuff when it's the appropriate keycodes for up/down-arrow (38, 40), to keep a reference to which node (item in your div) you move the focus to.
Then call the same handler when you hit enter (keyCode 13) as you do onclick.
It's hard to give a coding-example because it highly depend on context, but a tip on how to navigate through your div is to make us of .nextSibling and .previousSibling, aswell as .firstChild and .childNodes.