How can i get my comboBox selection to work properly without a message box

I have in my c# application a combo box from which i  select a record and then
use the split command to get then items in the combo  (See Screen with the Combo box Below)


The problem i have is that ordinarily if i click on a record it show give me the last figure  exchange rate
in the exchange rate box.

What happen right no is that is i just click I dont get anything selected into the exchange rate box (see below)


Now when i introduced the message box and just click ok after the messagebox comes up i get the required result

see screen below.


Definitely i dont want my application to ship out with users having to Click ok on message box

How can i solve this problem.

There must be  a way to get the selection without  the message box

The detailed code is shown below:

[private void glTRANSCurrencyValue_SelectedIndexChanged(object sender, EventArgs e)
        {
            // Setting index to 0 at form load ensure that script below is not processed during combo initial load
            if (this.glTRANSCurrencyValue.SelectedIndex != 0)
            {
                glTRANSExchrateValue.Text = "0";
                System.Data.DataRowView selected_row = glTRANSCurrencyValue.SelectedItem as System.Data.DataRowView;
                // Always use this TryParse to determin a selected value. Thencomment ou the Message Box once satisfied
                bool isNumeric;
                int i;
                string str = glTRANSCurrencyValue.SelectedText.ToString();
                isNumeric = int.TryParse(str, out i);
                MessageBox.Show("The value of i is " + i);   // Always uncomment this line to see how TryParse worked

                string phrase = glTRANSCurrencyValue.SelectedText.ToString();
                string[] words = phrase.Split(' ');
                int j = 0;
                foreach (var word in words)   // Always put cursor on words to determine content of each field field[1] ..... field[n]. Can also Use switch to get the fields
                {
                    j += 1;

                    switch (j)
                    {
                        case 3:
                           
                            break;
                        case 5:
                            string var2 = $"{ word}";
                            glTRANSExchrateValue.Text = var2;
                            break;

                    }

                }
            }
        }[/code]



Please Help

Olukay