C#获取HTML文本框的值都是乱码,该怎么处理

   <form  name="referForm"action="new.aspx" method="post">   <span>发布标题：<input type="text" name="titletext" id="titletext" /><br></span>   <span>信息分类：<select name="selectMenu" id="selectMenu" class="sel" onchange="MenuBin()">        <option value="-1">-请选择分类-</option>        <option value="0">二手信息</option>        <option value="1">综合服务</option>        <option value="2">招聘求职</option>        <option value="3">生活消费</option>        <option value="4">教育培训</option>        <option value="5">同城寻缘</option>        <option value="6">公众信息</option>      </select>      <select name="selectClass" id="selectClass" class="sel">        <option value="-2" selected="selected">-请选择顶级分类-</option>      </select><br></span>       <span>地域位置：<select name="Address" id="Address" class="sel">        <option value="-1">请选择位置</option>        <option value="1">武昌区</option>        <option value="2">洪山区</option>        <option value="3">江岸区</option>        <option value="4">江汉区</option>        <option value="5">汉阳区</option>        <option value="6">硚口区</option>        <option value="7">其他</option>      </select><br></span>       <span>联系地址：<input type="text" name="contact"  id="contact" class="mytext" style="width:200px" />       <br></span>       <span>有效天数：<input type="text" name="day" id="day" style="width:40px"   onblur="erro()"/> <b id="dayerro" style="color:#FF0000; font-weight:normal; display:none; font-size:12px"><img src="images/erro.gif" />请正确输入天数!</b><br></span>      <span class="com"><h style="float:left">信息内容：</h><textarea name="comment" id="comment" class="mytext" style="width:400px;height:100px"></textarea><br></span>      <span class="com"><h style="float:left">联系方式：</h><textarea name="conttype" id="conttype" class="mytext" style="width:400px;height:100px">联系人：电话：邮箱：QQ：</textarea></span><Div class="btn">  <a href="javascript:Submit()"><img src="images/btn.gif"  border="0"/></a></Div></form>

protected void Page_Load(object sender, EventArgs e)    {        if (!IsPostBack)        {            Hashtable hash = new Hashtable();            SqlString sqltr = new SqlString();            hash.Add("InfoTitle",sqltr.GetQuotedString( Request.Params["titletext"].ToString()));//标题            hash.Add("InfoMenuId", sqltr.GetQuotedString(Request.Params["selectMenu"].ToString()));//一级分类ID            hash.Add("InfoClassId", sqltr.GetQuotedString(Request.Params["selectClass"].ToString()));//二级分类ID            hash.Add("InfoIP", sqltr.GetQuotedString(Request.UserHostAddress.ToString()));//获取用户IP地址            hash.Add("InfoLocal", sqltr.GetQuotedString(Request.Params["Address"].ToString()));//地理位置            hash.Add("InfoAddress", sqltr.GetQuotedString(Request.Params["contact"].ToString()));//联系地址            hash.Add("InfoDay", sqltr.GetQuotedString(Request.Params["day"]));//有效天数            hash.Add("InfoContace", sqltr.GetQuotedString(Request.Params["conttype"].ToString()));//联系方式            hash.Add("InfoComment", sqltr.GetQuotedString(Request.Params["comment"].ToString()));//信息内容            hash.Add("InfoTOP", 0);//是否置顶            hash.Add("InfoDate", sqltr.GetQuotedString(DateTime.Now.ToString()));//当前时间            User user = new User();            if (user.AddInfo(hash))            {                Response.Redirect("default.aspx");            }        }    }