c# winform How to save to CSV to any directory

How can i save a csv file to the directory of choice? The below saves to the program dir. I tried Save file dialog but cant figure it out. I have a datagridview that's populated from import of an excel file.

      #region Write to CSV
        public void writeCSV(DataGridView gridIn, string outputFile)
        {
            //test to see if the DataGridView has any rows
            if (gridIn.RowCount > 0)
            {
                string value = "";
                DataGridViewRow dr = new DataGridViewRow();
                StreamWriter swOut = new StreamWriter(outputFile);

                //write header rows to csv
                for (int i = 0; i <= gridIn.Columns.Count - 1; i++)
                {
                    if (i > 0)
                    {
                        swOut.Write(",");
                    }
                    swOut.Write(gridIn.Columns[i].HeaderText);
                }

                swOut.WriteLine();

                //write DataGridView rows to csv
                for (int j = 0; j <= gridIn.Rows.Count - 1; j++)
                {
                    if (j > 0)
                    {
                        swOut.WriteLine();
                    }

                    dr = gridIn.Rows[j];

                    for (int i = 0; i <= gridIn.Columns.Count - 1; i++)
                    {
                        if (i > 0)
                        {
                            swOut.Write(",");
                        }

                        value = dr.Cells[i].Value.ToString();
                        //replace comma's with spaces
                        value = value.Replace(',', ' ');
                        //replace embedded newlines with spaces
                        value = value.Replace(Environment.NewLine, " ");

                        swOut.Write(value);
                    }
                }
                swOut.Close();
            }
        }

        #endregion




        #region CSV Button

        private void button3_Click(object sender, EventArgs e)
        {


            writeCSV(dataGridView1, "result.csv");
            MessageBox.Show("Converted successfully to *.csv format");
        }

        
        #endregion

Booney440