Populate Textbox Based on Another

[Lafammm]

Hi Guys,
I have a c# asp.net application which has a textbox that take a user input. (I'll call this TB1 for this example).
Currently only 2 'words' are used to populate this text box they are: "1Series" and "XF".
When TB1 is populated with "1Series" I would like another textbox (TB2) to populate with "BMW".
When TB2 is populated with "XF" I would like TB2 to populate with "Jaguar".
This application may expand so I would like scope to be able to add as many statements as I can.

I am then taking the values and adding them to a .edi file using WriteAllText just for a bit of context.
Thanks in Advance!

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[jmcilhinney]

My first question is, if that first TextBox can only be populated with two possible values, why isn't it a DropDownList?