关于留言本的实现，请各位高手帮我填写关键代码

附件中是一个留言本程序，其中关键代码
post.aspx 中的提交函数，不知怎样实现，请大家帮我解决    protected void button1_Click(object sender, EventArgs e)
    {    }post.aspx 文件如下<%@ Page Language="C#" %><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><script runat="server">
    protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
    {
        Image1.ImageUrl ="face/"+ DropDownList1.SelectedValue.ToString();   
    }    protected void button1_Click(object sender, EventArgs e)
    {    }
</script><html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>无标题页</title>
</head>
<body>
    <form id="form1" runat="server">
  <table width="730" border="0">
    <tr>
      <td width="103"> </td>
      <td width="597"><img src="gif/logo.gif" width="253" height="34"></td>
      <td width="16"> </td>
    </tr>
    <tr>
      <td><span class="style3">留言标题：</span></td>
      <td><span class="style3">
        <input name="title" type="text" id="title" runat="server" >
        *必填
        <asp:requiredfieldvalidator ID="Requiredfieldvalidator1" ControlToValidate="title" Display="Static" EnableClientScript="true" ErrorMessage="对不起！请输入留言标题！" runat="server" />        
      </span></td>
      <td> </td>
    </tr>
    <tr>
      <td><span class="style3">昵    称：</span></td>
      <td><span class="style3">
        <input name="MessageName" type="text" id="MessageName" runat="server" >
        *必填
        <asp:requiredfieldvalidator ID="Requiredfieldvalidator2" ControlToValidate="MessageName" Display="Static" EnableClientScript="true" ErrorMessage="对不起！请输入你的昵称！" runat="server" />         
      </span></td>
      <td> </td>
    </tr>
    <tr>
      <td><span class="style3">个人主页：</span></td>
      <td><span class="style3">
        <input name="PageUrl" type="text" id="PageUrl" runat="server" >
        <asp:regularexpressionvalidator ID="Regularexpressionvalidator1" ControlToValidate="PageUrl" Display="Static" ErrorMessage="对不起！你输入的主页网址格不对！（要http://）" runat="server"  ValidationExpression="http://([\w-]+\.)+[\w-]+(/[\w- ./?%&=]*)?" />        
      </span></td>
      <td> </td>
    </tr>
    <tr>
      <td><span class="style3">电子邮箱：</span></td>
      <td><span class="style3">
        <input name="Email" type="text" id="Email" runat="server" >
        <asp:regularexpressionvalidator ID="Regularexpressionvalidator2" ControlToValidate="Email" Display="Static" EnableClientScript="true" ErrorMessage="对不起！你输入的电子邮箱地址格式不对！" runat="server" ValidationExpression="\w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*" />        
      </span></td>
      <td> </td>
    </tr>
    <tr>
      <td><span class="style3">QQ号码：</span></td>
      <td><span class="style3">
        <input name="Qicq" type="text" id="Qicq" runat="server" >
        <asp:rangevalidator ControlToValidate="Qicq" Display="Static" ErrorMessage="请输入正确的QQ号码！" ID="rang" MaximumValue="999999999999999" MinimumValue="10000" runat="server" />        
      </span></td>
      <td> </td>
    </tr>
    <tr>
      <td><span class="style3">选择头像：</span></td>
      <td rowspan=2><span class="style3">  
           <asp:Image ID="Image1" runat="server" Height="195px" Width="224px" ImageUrl="~/face/face1.GIF" /><br />          </span></td>
      <td> </td>
    </tr>
      <tr>
          <td>   
          <asp:DropDownList ID="DropDownList1" runat="server" AutoPostBack="True" OnSelectedIndexChanged="DropDownList1_SelectedIndexChanged"
            Width="100px">
            <asp:ListItem Selected="True">face1.gif</asp:ListItem>
            <asp:ListItem>face2.gif</asp:ListItem>
            <asp:ListItem>face3.gif</asp:ListItem>
            <asp:ListItem>face4.gif</asp:ListItem>
            <asp:ListItem>face5.gif</asp:ListItem>
        </asp:DropDownList>        
                    <br />
                    <br />
                    <br />
              <br />
                    <br />
                </td>
          <td>   </td>
      </tr>    
    <tr>
      <td><span class="style3">选择表情：</span></td>
      <td><p class="style1 style4">
          <input type=radio name=Miange value=Miange/FIL1.GIF checked >
          <img src="Miange/FIL1.GIF" border="0" >
          <input type=radio name=Miange value=Miange/FIL7.GIF>
          <img src="Miange/FIL7.GIF" border="0" >
          <input type=radio name=Miange value=Miange/FIL8.GIF>
          <img src="Miange/FIL8.GIF" border="0" >
          <input type=radio name=Miange value=Miange/FIL11.GIF>
          <img src="Miange/FIL11.GIF" border="0" >
          <input type=radio name=Miange value=Miange/FIL12.GIF>
          <img src="Miange/FIL12.GIF" border="0" >        </p>
        <p class="style3">          
          <input type=radio name=Miange value=Miange/FIL5.GIF>
          <img src="Miange/FIL5.GIF" border="0" >
          <input type=radio name=Miange value=Miange/FIL39.GIF>
          <img src="Miange/FIL39.GIF" border="0" >
          <input type=radio name=Miange value=Miange/FIL42.GIF>
          <img src="Miange/FIL42.GIF" border="0" >
          <input type=radio name=Miange value=Miange/FIL50.GIF>
          <img src="Miange/FIL50.GIF" border="0" >
          <input type=radio name=Miange value=Miange/FIL47.GIF>
          <img src="Miange/FIL47.GIF" border="0" ></p></td>
      <td> </td>
    </tr>
    <tr>
      <td><span class="style3">留言内容：</span></td>
      <td><span class="style3">
        <textarea name="MessageBook" cols="65" rows="10" id="MessageBook" runat="server" ></textarea>
        *必填
        <asp:requiredfieldvalidator ID="Requiredfieldvalidator3" ControlToValidate="MessageBook" Display="Static" EnableClientScript="true" ErrorMessage="对不起！请输入留言内容！" runat="server" />        
</span></td>
      <td> </td>
    </tr>
    <tr>
      <td> </td>
      <td>
        <div align="left"></div>        
        <div align="center">
          <asp:button ID="button1" runat="server" Text="发表" OnClick="button1_Click" />          
   
<input id="Reset1" type="reset" name="Submit2" value="重写" runat="server" ><a href="index.aspx">查看留言 </a></div>      </td>
      <td> </td>
    </tr>
    <tr>
      <td> </td>
      <td><div align="center"><span class="style3"> 程序设计：B.A.D </span></div></td>
      <td> </td>
    </tr>
    <tr>
      <td> </td>
      <td> </td>
      <td> </td>
    </tr>
  </table>
        
    </form>
</body>
</html>