Here goes my GUI

lol, ok. Thank you Vulpes

Ah ok , now it all makes, and it all works perfectly Vulpes, tyvm!

except this doesn't make sense

          int num = deck[lastCardIndex]; //index = 0
            lastCardIndex++;
            suit = suits[(num - 1) % 4]; // tells us what suit it is
            return (num - 1) / 4 + 1;

so   lastCardIndex has 0 which assigns it to deck and then to num

but why do we increment lastCardIndex?

and then, we do the math , suit [num-1] <<< but the num is zero! because of the the statement above


and then this suit = suits[(num - 1) % 4]     , I understand the whole modulus thing now, how it assings 1-3 a number and it determines the suit, but how does the computer know to assign particularly that number to cards array?

To do the replay thing, remove this line from button1_Click:

            deal = 0; // start again on next button click 

and replace it with these:

            button1.Enabled = false;
            DialogResult dr = MessageBox.Show("Want to play again?", "Replay", MessageBoxButtons.YesNo);
            if (dr == DialogResult.Yes)
            {
                button1.Enabled = true;
                deal = 0; // start again on next button click
            }

If they don't want to play again and you want to close the application at that point, just add:

           else this.Close();

A new line in Windows is supposed to be "\r\n" and in Unix it's "\n". See the docs for the Environment.NewLine property:

http://msdn.microsoft.com/en-us/library/system.environment.newline.aspx 

However, "\n" still seems to work in some types of Windows applications such as console applications.

And


            int num = deck[lastCardIndex]; //index = 0
            lastCardIndex++;
            suit = suits[(num - 1) % 4]; // tells us what suit it is
            return (num - 1) / 4 + 1;

so   lastCardIndex has 0 which assigns it to deck and then to num

but why do we increment lastCardIndex?

and then, we do the math , suit [num-1] <<< but the num is zero! because of the the statement above


and then this suit = suits[(num - 1) % 4]     , I understand the whole modulus thing now, how it assings 1-3 a number and it determines the suit, but how does the computer know to assign particularly that number to cards array?

so \r\n is like new line?

but isn't \n is new line?

then why \r is in there?

By the way, you were correct, I forgot to type +.... lol

Vulpes, what if after 26 deals play button would disappear and window would pop up saying

want to play again?

yes         no

How would I do that

I mean that, rather than clearing the old code and pasting the new code in, you've gone through the old code line by line and altered it where needed.

whats piecemeal fashion?

It shouldn't do - it should show all 26.

However, if you click the button again after that, it will erase the previous deals and start again with a new batch of 26 deals.

If you've altered the code in a piecemeal fashion, I'd check that you've using:

  outputTextBox.Text += temp;  

rather than:

  outputTextBox.Text = temp;

Vulpes thank you so much, but now there's another problem, when i click play it new deal erases the old deal, but I want the old deal to be visible as well. So all 26 deals are visible, and i can just scroll back and forth, pretty much like before.

OK, we can do that.

First you need to add the following to your fields - I've made them static as your other fields are static but it doesn't really matter:

static int totalComputer = 0;
static int totalPlayer = 0;
static int deal = 0;

You'll also need to resurrect your outputLabel and I'd change the font to the fixed-width Consolas to make layout easier. 

Now you need to change the code in the button1_Click eventhandler as follows:

public void button1_Click(object sender, EventArgs e)
{
    if (deal == 0)
    {
        totalComputer = 0;
        totalPlayer = 0;
        Array.Clear(deck, 0, deck.Length);
        lastCardIndex = 0;
        FillDeck();
        outputTextBox.Clear();
        outputLabel.Text = "";
    }
           
    string computerSuit;
    int computer = SelectCard(out computerSuit) - 1;
    string playerSuit;
    int player = SelectCard(out playerSuit) - 1;

    if (computer > player)
    {
        totalComputer += 2;
    }
    else if (computer < player)
    {
        totalPlayer += 2;
    }
    else
    {
        totalComputer += 1;
        totalPlayer += 1;
    }
             
    string temp = String.Format("Deal # {0}\r\n", deal + 1);
    temp += String.Format(" Computer has {0} of {1}\r\n", cards[computer], computerSuit);
    temp += String.Format(" Player has {0} of {1}\r\n", cards[player], playerSuit);
    temp += String.Format("Computer Score is {0}\r\n", totalComputer);
    temp += String.Format("Player Score is {0}\r\n", totalPlayer); 

    if (deal < 25) temp += "\r\n";

    outputTextBox.Text += temp;
    outputTextBox.SelectionStart = outputTextBox.Text.Length; // place caret at end of text
    outputTextBox.ScrollToCaret(); // make sure last deal is visible
    deal++;

    if (deal < 26) return;          
    if (totalComputer > totalPlayer)
    {
        temp = "THE WINNER IS THE COMPUTER!";
    }
    else if (totalPlayer > totalComputer)
    {
        temp = "THE WINNER IS THE PLAYER!";
    }
    else
    {
        temp = "IT'S A DRAW!";
    }

    temp += "\r\n\r\n" + "           FINAL SCORE\r\n";
    temp += "Computer               Player\r\n";
    temp += "   " + totalComputer + "                         " + totalPlayer;
    outputLabel.Text = temp;
    deal = 0; // start again on next button click
}

Awesome, but you know vulpes, I am thinking will it look better if final score will be displayed separately in outputLabel?

something like.

THE WINNER IS (whoever is the winner) or DRAW


                         FINAL SCORE

Computer                                        Player






Also click play button every time for  26 deals