我开发的注册网页遇到的问题

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;


public partial class ideas : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
         if (PreviousPage != null)
        {
            if(PreviousPage.IsCrossPagePostBack)
                

            string username=(((TextBox)PreviousPage.FindControl("username"))).Text;
            string password=(((TextBox)PreviousPage.FindControl("password"))).Text;
            string sex=(((TextBox)PreviousPage.FindControl("sex"))).Text;
            string age=(((TextBox)PreviousPage.FindControl("age"))).Text;
            string birth=(((TextBox)PreviousPage.FindControl("birth"))).Text;
            string email=(((TextBox)PreviousPage.FindControl("email"))).Text;
            string qq=(((TextBox)PreviousPage.FindControl("qq"))).Text;
            string address=(((TextBox)PreviousPage.FindControl("address"))).Text;

            string connectionstring="data source=.;Initial catalog=用户注册信息;Integrated Security=true;";

            using(sqlconnection conn=new SqlConnection(connectionstring))
            {
                string sqlstr="Insert into zhuce(username,password,sex,age,birth,email,qq,address) values(@username,@password,@sex,@age,@birth,@email,@qq,@address)";
                SqlCommand comm=new SqlCommand(sqlstr,conn);

                comm.Parameters.AddWithValue("@username",username);
                comm.Parameters.AddWithValue("@password",password);
                comm.Parameters.AddWithValue("@sex",sex);
                comm.Parameters.AddWithValue("@age",age);
                comm.Parameters.AddWithValue("@birth",birth);
                comm.Parameters.AddWithValue("@email",email);
                comm.Parameters.AddWithValue("@qq",qq);
                comm.Parameters.AddWithValue("@address",address);


                conn.Open();
                comm.EndExecuteNonQuery();

                Response.Write("<script>alert(\"注册成功\")</script>");

}
    }
}
}遇到问题是：
嵌入的语句不能是声明或标志语句，请各位高手指教... --------------------编程问答-------------------- 觉得你connectionstring写的有问题 --------------------编程问答-------------------- 觉得你connectionstring写的有问题 --------------------编程问答-------------------- --------------------编程问答-------------------- 是不是connectionstring应该是 static string 啊？  你试试看 --------------------编程问答-------------------- 我找出问题了，是我的sql数据库服务器名有问题

补充：.NET技术 ,  ASP.NET