【小白提问】帮忙找找出错的代码并修改

[ShengLitong]

string username;
string password;
string password2;
string name;
string sex;
string idcard;
string telephone;
string email;
string paytreasure;
string wechat;
string qq;
string address;
string national;
string hobby;

string message;

username = tbusername.Text;
password = tbpassword.Text;
password2 = tbpassword2.Text;
name = tbname.Text;
sex = listsex.Text;
idcard = tbidcard.Text;
telephone = tbtelephone.Text;
email = tbemail.Text;
paytreasure = tbpaytreasure.Text;
wechat = tbwechat.Text;
qq = tbqq.Text;
address = tbaddress.Text;
national = tbnational.Text;
hobby = tbhobby.Text;

lbusername.Text = "";
lbpassword.Text = "";
lbpassword2.Text = "";
lbname.Text = "";
lbidcard.Text = "";
lbtelephone.Text = "";
lbemail.Text = "";
lbpaytreasure.Text = "";
lbwechat.Text = "";
lbqq.Text = "";
lbaddress.Text = "";
lbnational.Text = "";
lbhobby.Text = "";


if (username.Trim() == "")
{
lbusername.Text = "用户名不能为空！";
return ;
}
if (password.Trim() == "")
{
lbpassword.Text = "密码不能为空！";
return ;
}
if (password2.Trim() == "")
{
lbpassword2.Text = "确认密码不能为空！";
return ;
}
if (name.Trim() == "")
{
lbname.Text = "用户名不能为空！";
return ;
}
if (idcard .Trim () == "")
{
lbidcard.Text = "身份证不能为空！";
return ;
}
if (telephone.Trim() == "")
{
lbtelephone.Text = "联系电话不能为空！";
return ;
}
if (email.Trim() == "")
{
lbemail.Text = "邮箱不能为空！";
return ;
}
if (paytreasure.Trim() == "")
{
lbpaytreasure.Text = "支付宝不能为空！";
return ;
}
if (wechat.Trim() == "")
{
lbwechat.Text = "微信不能为空！";
return ;
}
if (qq.Trim() == "")
{
lbqq.Text = "qq不能为空！";
return ;
}
if (address.Trim() == "")
{
lbaddress.Text = "地址不能为空！";
return ;
}
if (national.Trim() == "")
{
lbnational.Text = "民族不能为空！";
return ;
}
if (hobby.Trim() == "")
{
lbhobby.Text = "爱好不能为空！";
return ;
}
//3.2长度是否合法
if (username.Length > 10)
{
lbusername.Text = "用户名不能超过20个长度！";
return ;
}
if (password.Length > 18)
{
lbpassword.Text = "密码不能超过18个长度！";
return ;
}
if (idcard .Length !=18)
{
lbidcard.Text = "身份证必须为18位！";
return;
}
//3.3内容是否合法
if (password.Trim() != password2.Trim())
{
lbpassword2.Text = "两次输入的密码不一致！";
return;
}

string mycon;
mycon = "server=.;uid=sa;pwd=123;database=shoppingonline15ds6-22";
SqlConnection conn = new SqlConnection(mycon);


string sql;
sql = "insert into customers(username,password,name,sex,idcard,telephone,email,paytreasure,wechat,qq,address,national,hobby)values(@username,@password,@name,@sex,@idcard,@telephone,@email,@paytreasure,@wechat,@qq,@address,@national,@hobby)";

SqlCommand comm = new SqlCommand(sql,conn);
comm.Connection.Open();

comm.Parameters.Add(new SqlParameter ("@username",SqlDbType.VarChar));
comm.Parameters["@username"].Value = username;
comm.Parameters.Add(new SqlParameter("@password", SqlDbType.VarChar));
comm.Parameters["@password"].Value = password;
comm.Parameters.Add(new SqlParameter("@name", SqlDbType.VarChar));
comm.Parameters["@name"].Value = name;
comm.Parameters.Add(new SqlParameter("@sex", SqlDbType.VarChar));
comm.Parameters["@sex"].Value = sex;
comm.Parameters.Add(new SqlParameter("@idcard", SqlDbType.VarChar));
comm.Parameters["@idcard"].Value = idcard;
comm.Parameters.Add(new SqlParameter("@telephone", SqlDbType.VarChar));
comm.Parameters["@telephone"].Value = telephone;
comm.Parameters.Add(new SqlParameter("@email", SqlDbType.VarChar));
comm.Parameters["@email"].Value = email;
comm.Parameters.Add(new SqlParameter("@paytreasure", SqlDbType.VarChar));
comm.Parameters["@paytreasure"].Value = paytreasure;
comm.Parameters.Add(new SqlParameter("@wechat", SqlDbType.VarChar));
comm.Parameters["@wechat"].Value = wechat;
comm.Parameters.Add(new SqlParameter("@qq", SqlDbType.VarChar));
comm.Parameters["@qq"].Value = qq;
comm.Parameters.Add(new SqlParameter("@address", SqlDbType.VarChar));
comm.Parameters["@address"].Value = address;
comm.Parameters.Add(new SqlParameter("@national", SqlDbType.VarChar));
comm.Parameters["@national"].Value = national;
comm.Parameters.Add(new SqlParameter("@hobby", SqlDbType.VarChar));
comm.Parameters["@hobby"].Value = hobby;

// try
// {
comm.ExecuteNonQuery();
message = "注册成功！";
// }
// catch (SqlException)
// {
// message = "注册失败，请重新注册！";
//}
comm.Connection.Close();

//把结果输出到label

lbmessage.Text = message;

[ShengLitong]