Display even numbers smaller than the value that the user chooses (from big to small) in c sharp

Question

System.Console.Write("Please enter a number: ");
String numberString = Console.ReadLine();
int index = System.Convert.ToInt32(numberString);
int number = index;
if (index % 2 == 0)
{
number = index;
}
else
{
number = index - 1;
}

for (int i = 0; i <= index; i++)
{
if (number % 2 == 0 && number > 0)
{
System.Console.WriteLine(number);
number -= 2;
}
}

//***********************************
how to write in another way with for loop and with while ?

Answer 1

// ie in this way:

String numberString = Console.ReadLine();

while(numberString != "e") {

// you code

numberString = Console.ReadLine();

// all the code will repeated
// until user enter e
}