C# macro for a CNC machine to write co-ordinates to a CSV file

Question

I am using a webacm attached to a CNC machine to provide the user a view of the part to be machined. As they jog around the area I want to allow them to record the X & Y co-ordinates of points of interest.

These points are read from internal system registers called Xmachpos and Ymachpos then written to a CSV file.

When I try to run the macro I get a CS1513 for missing "}" and a CS1022 name space EOF error but cannot see what I am missing.

Any help much appreciated

using System;
using System.IO;
using System.Windows.Forms;

class Program
{
    static void Main(string[] args)
    {
        string filePath = @"C:\dxf.txt";
        int Xpos, Ypos;

        //Check if file exists and create it if not
        if (!File.Exists(filePath))
        {
            File.Create(filePath).Close();
        }

        //Write Xpos and Ypos values to file and prompt user to enter more values
        do
        {
            Xpos = exec.GetXmachpos();
            Ypos = exec.GetYmachpos();
            using (StreamWriter writer = File.AppendText(filePath))
            {
                writer.WriteLine(Xpos.ToString() + "," + Ypos.ToString());
            }
        } while (PromptUser());

        MessageBox.Show("Values written to file. Click OK to exit.");
    }

    static bool PromptUser()
    {
        DialogResult result = MessageBox.Show("Do you want to enter more values?", "Enter Values", MessageBoxButtons.YesNo, MessageBoxIcon.Question);
        return (result == DialogResult.Yes);
    }
}

Also tried the system vendor forum pages but no luck there