js为什么会刷新本页
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="GProductsList.aspx.cs" Inherits="GProductsList" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>无标题页</title>
<script type="text/javascript">
function MySearch()
{
document.getElementById("Error").style.display="block";
}
</script>
</head>
<body>
<form id="form1" runat="server">
<input type="image" src="Search.gif" onclick="MySearch();"/>
<div style="margin-top:40px; margin-bottom:0px; margin-left:100px; display:none; text-align:center; float:left; left:400px; top:45px; position:absolute;" id="Error">
<img src="/images/Please-input-a-search-term.gif" />
</div>
<div style=" clear:both;"></div>
</form>
</body>
</html>
//------------------------
为什么我点搜索时候会刷新本页?