Cannot implicitly convert type "string" to "int"

[BioPhysEngr]

The code I'm using now is exactly the same as the last one I posted.

(1) The error is a compiler error.
(2) The exact error message is "Cannot implicitly convert type "string" to "int".
(3) Line 21, column 25. It's the "guess = Console.WriteLine();" line.

Sorry for getting distracted with the goto discussion. The problem is as follows:

guess is declared as an int. Console.ReadLine() returns a string. You are trying to assign a variable of one type to a variable of a different type. In general, this is not allowed. You must first convert the string to an int. Do this like:

guess = Int32.Parse(Console.ReadLine());

Or even better

bool valid = false;
while( !valid )
{
    //Try to convert the string typed in to an integer and store it in guess
    //Valid will be assigned true only if this parsing succeeds.
    valid = Int32.TryParse(Console.ReadLine(), out guess);
}

The difference between Int32.Parse(string) and Int32.TryParse(string, out int) is that the former will convert the string to an int and throw an exception if given invalid input. The latter will convert a string to an int and give you a return value (bool) indicating whether or not the parsing was successful.