exchange it with jquery

[runeveryday]

  <div id="orderprice">
    <a href="http://localhost/job/index.php?main_page=index&cPath=<?php echo $_GET['cPath'];?>&sort=3a">Price Up</a> 
    <a href="http://localhost/job/index.php?main_page=index&cPath=<?php echo $_GET['cPath'];?>&sort=3d">Price Down</a></div>
<div id="ordername">
<a href="http://localhost/job/index.php?main_page=index&cPath=<?php echo $_GET['cPath'];?>&sort=2a">Name Up </a> 
<a href="http://localhost/job/index.php?main_page=index&cPath=<?php echo $_GET['cPath'];?>&sort=2d">Name Down </a></div>

when the user click Price Up the Price Down show, Price Up text hide. vice versa。

ps: why this can't work?

$("#orderprice a,#ordername a").eq(1).hide();

[programthis]

I'm not sure if this is what you're trying to do? Show the link for Price Up by default, then if Price Up is clicked that link should be hidden and Price Down shows?

If so, you could do this:
First, put an id on the Price Up and Price Down anchor tags - id="priceUp" & id="priceDown", respectively.

/* First, hide the Price Down link by default */
$("#priceDown").hide();

/* Hide Price Up on click and show Price Down */
$("#priceUp").click(function(){
  $(this).hide();
  $("#priceDown").show();
});

/* Hide Price Down link on click and show Price Up */
$("#priceDown").click(function(){
  $(this).hide();
  $("#priceUp").show();
});