Visual Studio, Make textbox choose between Different values

I'm pretty new to Visual Studio (2005). I have a textbox which must display 2 different strings based on another textbox field.

Example
Textbox 1开发者_Go百科 = "Education"
Textbox 2 Needs to be "Date"
but if
Textbox 1 = "Language"
Textbox 2 needs to be "Knowledge"

I have trying some Iif functions, but I can't get it right. How can I fix this?

in the change event of the OTHER textbox you can change the text. or use a business layer and databinding.