Someone

<html>
<head>
  <script src="http://code.jquery.com/jquery-latest.js"></script>  
  <script>
	  $(document).ready(function(){		
			$(".box").hover(mHv, uHv);
			function mHv(){ $(this).css('border', '1px solid red'); }
			function uHv(){ $(this).css('border', '1px solid blue'); }
	  });
  </script>

  <style type="text/css">	
	.box {
		float:left;
		width:100px;
		height:100px;
		margin-right:5px;
		border: 1px solid blue;
	}
	#main {
		align: center;
		width: 50%;
		border: 1px solid;
	}
  </style>

</head>
<body>
<div id="main">
	<div style="clear:both; padding-top:15px;">
		<div class="box" id="a0"></div>
		<div class="box" id="a1"></div>
		<div class="box" id="a2"></div>
		<div class="box" id="a3"></div>
		<div class="box" id="a4"></div>
	</div>
	<div style="clear:both; padding-top:5px;">
		<div class="box" id="b0"></div>
		<div class="box" id="b1"></div>
		<div class="box" id="b2"></div>
		<div class="box" id="b3"></div>
		<div class="box" id="b4"></div>
	</div>
	<div style="clear:both; padding-top:5px;">
		<div class="box" id="c0"></div>
		<div class="box" id="c1"></div>
		<div class="box" id="c2"></div>
		<div class="box" id="c3"></div>
		<div class="box" id="c4"></div>
	</div>
	<div style="clear:both; padding-top:5px;">
		<div class="box" id="d0"></div>
		<div class="box" id="d1"></div>
		<div class="box" id="d2"></div>
		<div class="box" id="d3"></div>
		<div class="box" id="d4"></div>
	</div>
	<div style="clear:both; padding-top:5px;">
		<div class="box" id="e0"></div>
		<div class="box" id="e1"></div>
		<div class="box" id="e2"></div>
		<div class="box" id="e3"></div>
		<div class="box" id="e4"></div>
	</div>
</div>
</body>
</html>