private void checkAndSetForKnapsack() { if (tbN.Text.Equals(string.Empty)) { MessageBox.Show("N can't be empty!", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error); return; } else if (tbM.Text.Equals(string.Empty)) { MessageBox.Show("M can't be empty!", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error); return; } else if (tbData.Text.Equals(string.Empty)) { MessageBox.Show("You have to enter text to crypt!", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error); return; } this.specs.Add("n", Encoding.UTF8.GetBytes(tbN.Text)); this.specs.Add("m", Encoding.UTF8.GetBytes(tbM.Text)); if (!algoritham.SetAlgorithamProperties(specs)) { MessageBox.Show("Invalid properties!", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error); return; } }