I am taking the input from a text box then looping though it backward and creating the output string. after the loop is done I test the input text against the output text. If its true then its Palindrome.

 private void palindromeTest_bt_Click(object sender, RoutedEventArgs e)
        {
            if (palindromeInput_tb.Text != string.Empty)
            {
                string inputText = palindromeInput_tb.Text;
                string outputText = string.Empty;
                string letter = string.Empty;
                for (int i = inputText.Length - 1; i >= 0; i--)
                {
                    letter = inputText.Substring(i, 1);
                    outputText += letter;
                }
                if (inputText == outputText)
                { MessageBox.Show("Text is Palindrome"); }
                else
                { MessageBox.Show("Text is Not Palindrome"); }
            }
        }