HOA4

namespace HOA4_12WAL11FresnidoFarah
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void label1_Click(object sender, EventArgs e)
        {


        }

        private void button1_Click(object sender, EventArgs e)
        {
            string weight1 = textBox1.Text;
            string height1 = textBox2.Text;

            if ((textBox1.Text == "" || textBox2.Text == "") || (textBox1.Text == "" && textBox2.Text == ""))
            {
                MessageBox.Show("Error: Don't leave anything blank.");
            }
            else if (textBox1.Text != "" && textBox2.Text != "")
            {
                double weight = double.Parse(textBox1.Text);
                double height = double.Parse(textBox2.Text);

                double BMI = (weight * 0.45) / ((height * 0.025) * (height * 0.025));
                label3.Text = "BMI: " + BMI;

                textBox1.Text = "";
                textBox2.Text = "";
            }
        }

        private void button2_Click(object sender, EventArgs e)
        {
            string start1 = textBox3.Text;
            string end1 = textBox4.Text;

            if ((textBox3.Text == "" || textBox4.Text == "") || (textBox3.Text == "" && textBox4.Text == ""))
            {
                MessageBox.Show("Error: Don't leave anything blank.");
            }
            else if (textBox3.Text != "" && textBox4.Text != "")
            {
                double start = double.Parse(textBox3.Text);
                double end = double.Parse(textBox4.Text);

                if (end < start)
                {
                    MessageBox.Show("Error: Starting value has to be less than the ending value.");
                }
                else if (end > start)
                {

                    double n = end - start + 1;
                    double sum = n * ((end + start) / 2);

                    label6.Text = "The sum is " + sum;

                    textBox3.Text = "";
                    textBox4.Text = "";
                }
            }
        }
    }
}