calculate with metrics

[Yustme]

Hi,

I'm trying to make a project which "converts" for example from meters to centimeters. I fill 20 labels with a random generated question containing a "fromUnit" and "toUnit" object.

Here is my code:

public partial class Metrics : Form
   {
      private double[] _answer;
      private TextBox[] _textBox;
      private Label[] _labels;

      public Metrics()
      {
         InitializeComponent();
         this._answer = new double[20];
         this._textBox = new TextBox[20];
         this._labels = new Label[20];
         this.label1.Text = this.getQuestion(1, 10);
      }

      private string[][] lengths = new string[][]
      {
         new string[] {"kilometer", "1000"},
         new string[] {"hectometer", "100"},
         new string[] {"decameter", "10"},
         new string[] {"meter", "1"},
         new string[] {"decimeter", ".1"},
         new string[] {"centimeter", ".01"},
         new string[] {"millimeter", ".001"}
      };

      public string[] getUnit(int index)
      {
         return lengths[index];
      }

      private string getQuestion(int minLength, int maxLength)
      {
         // Create Random object
         Random rand = new Random((int)DateTime.Now.Ticks);

         int length = rand.Next(minLength, maxLength); // Gets the length to convert
         int randNumber1 = rand.Next(0, 6); // gets the first unit random number
         int randNumber2 = rand.Next(0, 6); // gets the second unit random number

         while (randNumber1 == randNumber2) // loop ensure that units are not the same
         {
            randNumber2 = rand.Next(0, 6);
         }

         string[] fromUnit = getUnit(randNumber1);  // gets the unit details from class
         string[] toUnit = getUnit(randNumber2);  // gets the unit details from class

         // gets the answer (i.e. (23 * .(01 / .001)) = 230)
         this._answer = length * (Convert.ToDouble(fromUnit[1]) / (Convert.ToDouble(toUnit[1])));

         //return the question string
         return "How much is " + length.ToString() + " " + fromUnit[0] + "(s) in " + toUnit[0] + "(s)?";
      }

      private void btnCalculate_Click(object sender, EventArgs e)
      {

      }

      private void FillLabelsWithQuestions()
      {
         foreach (Control label in this.Controls)
         {
            if (label is Label)
            {
               label.Text = getQuestion(1, 100);
            }
         }
      }
   }

The problem is, i don't know how to check if the answer is correct which is entered in a textbox and checks the answer when the button "calculate" is pressed, because there are strings involved too.

My labels are named like this:

label1
label2
label3
etc

And so are my textboxes:

textbox1
textbox2
.....

This is a screenshot of how my Form looks like:

http://i15.tinypic.com/49icglh.jpg

Anyone any suggestion?

Thanks in advance!

Have you heard of string compare?