Checking user input in a loop.

Question

I'm trying to request an answer from user, which is defined as:
string answer1 = Console.ReadLine();
Using IF and ELSE IF I can catch "Yes" or "No", but what if the answer will be completely different? I want user to receive repeated question each time he inserts a wrong answer, but unfortunately, previously defined answer1 cant be used inside WHILE loop. I tried this way:
while (answer1 != "Yes" || answer1 != "No")
{
Console.WriteLine("Please answer 'Yes' or 'No'");
//Here I want to check second answer.
}

Answer 1

set a label before requesting user input,
evaluate if the input is valid,
if is invalid goto label;
else proceed with your code

Answer 2

Not sure i understand it at the moment but working variant is:
string answer1 = Console.ReadLine();

while (!(answer1 == "Yes" || answer1 == "No"))
{
Console.WriteLine("\nProgram: Please answer 'Yes' or 'No'");
Console.Write("\n" + name + ": ");
answer1 = Console.ReadLine();
}