鼠标经过小图，显示大图

    <div class="container">
      <ul>
        <li><a href="b.jpg" class="preview"><img src="b.jpg" width="40" height="40" alt="gallery thumbnail" /></a></li>
        <li><a href="cc.jpg" class="preview"><img src="cc.jpg" width="40" height="40" alt="gallery thumbnail" /></a></li>
      </ul> 
    </div>
<style>
*{padding:0px;margin:0px;}
li{list-style:none; float:left;margin-left:10px;}
.container{
  width:1000px;
  height:600px;
  margin:0 auto;
  background:#FFC;
}
#preview { position:absolute; border:1px solid #ccc; background:#333; padding:5px; display:none; color:#fff; }
</style>
<script>
/*
 * Image preview script 
 * powered by jQuery (http://www.jquery.com)
 * 
 * written by Alen Grakalic (http://cssglobe.com)
 * 
 * for more info visit http://cssglobe.com/post/1695/easiest-tooltip-and-image-preview-using-jquery
 *
 */
 
this.imagePreview = function(){	
	/* CONFIG */
		
		xOffset = -30;
		yOffset = 10;
		
		// these 2 variable determine popup's distance from the cursor
		// you might want to adjust to get the right result
		
	/* END CONFIG */
	$("a.preview").hover(function(e){
		this.t = this.title;
		this.title = "";	
		var c = (this.t != "") ? "<br/>" + this.t : "";
		$("body").append("<p id='preview'><img src='"+ this.href +"' alt='Image preview' />"+ c +"</p>");								 
		$("#preview")
			.css("top",(e.pageY - xOffset) + "px")
			.css("left",(e.pageX + yOffset) + "px")
			.fadeIn("fast");						
    },
	function(){
		this.title = this.t;	
		$("#preview").remove();
    });	
	$("a.preview").mousemove(function(e){
		$("#preview")
			.css("top",(e.pageY - xOffset) + "px")
			.css("left",(e.pageX + yOffset) + "px");
	});			
};


// starting the script on page load
$(document).ready(function(){
	imagePreview();
});
</script>