How can I convert the text from a multiline textBox into XML

See more:

XML

VS2010

C#5.0

Inside a form I have a multiline textBox, in that textBox I have simply text, like this:

<VideoCard><brand id = '34' another = 'A'>PNY</brand><brand id = '43' other = 'B'>Gigabyte</brand></VideoCard>

and when I press a button, the text inside the first textBox will show in another textBox like this (with the identation and all that):

<VideoCard>
      <brand id = '34' another = 'A'>PNY</brand>
      <brand id = '43' other = 'B'>Gigabyte</brand>
</VideoCard>

How can I archieve that?

Note: I can't use LINQ