[RESOLVED] Change a text in richtextbox but keep image in it

[manhit45]

I have a richtextbox with images and text.
I want to change specified text but i want to keep my image.
How can i do that.
I use :

Dim aLines() As String = rtbDisplay.Lines
aLines(i) = aLines(i).Replace(str, "")
rtbDisplay.Lines = aLines

but do not work.