i have a question about to select the last line of the RichTextBox : <p>I have a Question to select the last line of the RichTextBox 
When i click the Button1 it will show the last line in the Messagebox </p>

<p>I tried a lot of codes by it only select the index of the lines 
i need your help</p>

<p>I want the output like </p>

<p>these are the lines i write in the RichTextBox</p>

<p>1.hello</p>

<p>2.world</p>

<p>3.welcome</p>

<p>when i click the button1 it will show the last line in messagebox</p>

<p>3.welcome   // it will appears in the message box</p>
