outputing text to a richtextbox. (NewLine?)

I need to output to a richtextbox. The problem is that when I use:

Code:

---

rtbMain.text = "First Line"
rtbMain.text = rtbMain.Text & "Second Line"

---

Puts all the text on one line. And:

Code:

---

rtbMain.text = "Line One"
rtbMain.text = "Line two"

---

Overwrites the the first.

So I need to know how to create a newline to output text to.
Or atleast simulate the enter key being pressed so I can get to the next line.

VB Code:

rtbMain.text = "First Line"
rtbMain.text &= ControlChars.Newline & "Second Line"
 
'or
rtbMain.AppendText ("First Line")
rtbMain.AppendText (ControlChars.Newline & "Second Line")

Thank you! Thats exactly what I was looking for.