ASP.NET投票系统提示框问题

1. protected void btnVote_Click(object sender, EventArgs e)
   {
       if(rbtlVote.SelectedIndex!=-1)
       {
           HttpCookie getCookie= Request.Cookies["Vote"];
           if(getCookie!=null)
           {
               Response.Write("<script>alert('你已经投过票了，不能重复投票！');
                   location='javascript:hisory.go(-1)'</script>");
   }
           else{
           int k= rbtlVote.SelectedIndex;
               count[k]= int.Parse(count[k].ToString())+1;
               putVote();
               HttpCookie vCookie = new HttpCookie("Vote");
               vCookie.Value="Vote";
               vCookie.Expires=DateTime.Now.AddDays(1);
               Response.Cookies.Add(vCookie);
               Response.Write("<script>alert('投票成功');</Script>");
           }
       }
   }
   

   Response.Write("alert(&#39;你已经投过票了，不能重复投票！&#39;);</p> <pre><code> 提示说：常量中有换行 </code></pre> <p>location=&#39;javascript:hisory.go(-1)&#39;");
   提示说：常量中有字符；

 location.href='javascript:hisory.go(-1)'</script>");