private bool IsValidInteger (out int result, TextBox txt, string name, int min = int.MinValue, int max = int.MaxValue)

{

// Give result an initial value.
result = int.MinValue;

// Get the text.
string text = txt.Text;

// If there is something wrong, build an error message.

string message = "";

if (text.Length == 0) message = "Please enter" + name + ".";

else if (!int.TryParse(text, out result))

message = "Error parsing" + name + "'" + text + "'";

else if ((result max))

message = name + " must be between " + min.ToString() + " and " + max.ToString() + ".";

// See if we have an error message.

if (message.Length > 0)

{

//Display the message, select the TextBox's text,

// give it focus, and return false.

MessageBox.Show(message, name + "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);

txt.Select(0, text.Length);

txt.Focus();

return false;

}

// The value is Okay.

return true;

}