MyControlLibrary.CharTabPage.Char4STR_TextChanged C# (CSharp) Method

        private void Char4STR_TextChanged(object sender, EventArgs e)
        {
            try
            {
                this.Group[3].SetSTR(Convert.ToInt32(Char4STR.Text));
                Char4STR_MOD.Text = this.Group[3].GetSTR_Mod().ToString();
            }
            catch
            {
                if (isError && !Char4STR.Text.Equals(""))
                {
                    ErrorMSG error = new ErrorMSG();
                    //set error message
                    error.ErrorLabel.Text = "Error: This box takes integers only (0-9)";
                    error.Show();
                    isError = false;
                    ///
                    Char4STR.Text = "";
                    ////
                    isError = true;
                }//end if
                if (Char4STR.Text.Equals(""))
                    Char4STR_MOD.Text = "0";
            }
        }