private void buttonDecrypte_Click(object sender, EventArgs e) { try { EncryptionRSA rsa = new EncryptionRSA(); TypeConversion tp = new TypeConversion(); richTextBoxDecryption.Text = tp.IntToChar(rsa.Dencryptor(richTextBoxDecryption.Text, textBoxPrivateKey.Text)); } catch (Exception ex) { MessageBox.Show("System Can not Decrypte your Message \n\nExplanation:\nPlease enter Correct Private Key and Correct Encrypted text\n\nException:" + ex.Message + "\n\nPress OK to Proceede"); } }