How do I make several choices in a text box [C#]?

ok, i'm ridiculously new c#, , i'm trying make small text adventure game in it, don't know how 1 thing without making tons of separate lines of code.

here's code have right now:

if (textbox1.text == "left")
{

messagebox.show("you walk short while before coming upon building, enter or keep walking?");

}

what i'm trying give them multiple things type in show same message box, can't remember how that, help?

not sure understood. like this?

if (textbox1.text == "left" || textbox1.text == "right" || textbox1.text == "fly") {     messagebox.show( ... ); }

Visual Studio Languages , .NET Framework > Visual C#

Gain