How could I manage number range output

Question

Updated form   http://www.4shared.com/rar/X2DWbFqF/LetItRide.html?refurl=d1url
If you go to the form I have three buttons, 1st is 5-100 range, 2nd is 25-500 range, and 3rd is 50-1000 range.

For example when I click 5-100 range the bet amount shouldn't be above or below that range.
I tried to do that:
        private void lowestBetButton_Click(object sender, EventArgs e)
            minBet = 5;
            maxBet = 100;
            if (playerbet < minBet && playerbet > maxBet)
            {
                MessageBox.Show("Bet must be between 5$ and 100$", "Bet range error");
            }
else
{
                middleBetButton.Enabled = false;
                topBetButton.Enabled = false;
                chipBet500Button.Visible = false;
                dealButton.Enabled = true;


                EnableChips(true);
}

But it doesnt work...