Thread: Can't Find what is wrong with my Code

import java.awt.*;
import java.applet.*;
import java.util.Random;
import javax.swing.*;
 
public class Unit04Lab extends Applet
{
 
//	Rectangle r11,r12,r13,r21,r22,r23,r31,r32,r33,r44,r34,r24,r14,r41,r42,r43;
	boolean scramble[];
	String matrix[][];
	Random rnd;
	int blankR;
	int blankC;
	int playLevel;
	Rectangle rect[][];
	int wid = 0;
	int gridSize = 0;
//	int grid = 0;
	int letterCount;
 
 
	public void init()
	{
		String prompt = "Enter Play Level \n 3 - 3x3 Grid \n 4 - 4x4 Grid \n 5 - 5x5 Grid";
		String gridLevel = JOptionPane.showInputDialog(prompt);
		gridSize = Integer.parseInt(gridLevel);
		wid =(600/gridSize);
 
		int x= 100;
		int y = 100;
		matrix =new String [gridSize+2][gridSize+2];
		rect= new Rectangle[gridSize+2][gridSize+2];
 
		for (int r=1; r<=gridSize; r++)
		{
			y=100;
			for (int c=1; c<=gridSize; c++)
			{
				rect[r][c] = new Rectangle(100+((r-1)*wid),100+((c-1)*wid),wid,wid);
				x +=wid;
			}
			y+=wid;
		}
 
 
		/*r11 = new Rectangle(100,100,200,200);
		r12 = new Rectangle(300,100,200,200);
		r13 = new Rectangle(500,100,200,200);
		r21 = new Rectangle(100,300,200,200);
		r22 = new Rectangle(300,300,200,200);
		r23 = new Rectangle(500,300,200,200);
		r31 = new Rectangle(100,500,200,200);
		r32 = new Rectangle(300,500,200,200);
		r33 = new Rectangle(500,500,200,200);
		r34 = new Rectangle(700,500,200,200);
		r24 = new Rectangle(700,300,200,200);
		r14 = new Rectangle(700,100,200,200);
		r41 = new Rectangle(100,700,200,200);
		r42 = new Rectangle(300,700,200,200);
		r43 = new Rectangle(500,700,200,200);
		r44 = new Rectangle(700,700,200,200);*/
 
		letterCount= gridSize * gridSize;
		scramble = new boolean[letterCount+1];
		for (int k = 1; k <letterCount+1; k++)
			scramble[k] = false;
		rnd = new Random();
 
		for (int r = 0; r <= gridSize+1; r++)
			for (int c = 0; c <= gridSize+1; c++)
				matrix[r][c] = "Y";
 
		for (int r = 1; r <= gridSize; r++)
		{
			for (int c = 1; c <= gridSize; c++)
			{
				matrix[r][c] = getLetter();
				if (matrix[r][c].equals("Y"))
				{
					blankR = r;
					blankC = c;
				}
			}
 
		}
	}
 
 
	public String getLetter()
	{
		String letter = "Y";
		boolean Done = false;
		int rndNum;
 
		while(!Done)
		{
			rndNum = rnd.nextInt(letterCount) + 1;
			if (scramble[rndNum] == false)
			{
				letter = String.valueOf((char) (rndNum+64));
				scramble[rndNum] = true;
				Done = true;
			}
System.out.println(letter);
		}
		return letter;
	}
 
 
	public void paint(Graphics g)
	{
		drawGrid(g);
		int y = 100;
		int x = 100;
			for( int r = 1; r <= gridSize; r++)
			{
				for( int c = 1; c <= gridSize; c++)
				{
					drawLetter(g,matrix[c][r],x,y);
					x += 200;
				}
			x = 100;
			y += 200;
			}
	}
 
 
	public void drawGrid(Graphics g)
	{
		int x = 100;
		int y = 100;
		int vert = 0;
 
		g.drawRect(100,100,600,600);
		for( wid =100; wid<= 700; x++);
			g.drawLine(x,y,x,y+100);
		for( y =100; y<=700; y++);
		{
			g.drawLine(vert,100,vert,700);
			g.drawLine(100,vert,700,vert);
		}
	}
 
 
/*	{
 
		g.drawRect(100,100,800,800);
		g.drawLine(300,100,300,900);
		g.drawLine(500,100,500,900);
		g.drawLine(100,300,900,300);
		g.drawLine(100,500,900,500);
		g.drawLine(700,100,700,900);
		g.drawLine(100,700,900,700);
	}*/
 
 
	public void drawLetter(Graphics g, String letter, int x, int y)
	{
		int offSetX = x + (int)(wid+15);
		int offSetY = y + (int)-(wid+15);
		g.setFont(new Font("Arial",Font.BOLD,wid));
		if (letter.equals("Y"))
		{
			g.setColor(Color.white);
			g.fillRect(x+1,y+1,wid+2,wid+2);
		}
		else
		{
			g.setColor(Color.black);
			g.drawString(letter,offSetX,offSetY);
		}
	}
 
 
	public boolean mouseDown(Event e, int x, int y)
	{
		int r=1;
		int c=1;
		for(r=1; r<=gridSize; r++)
		{
			for (c=1; c<=gridSize; c++)
			{
				if (rect[r][c]. contains(x,y) && okSquare(r,c)) {swap(c,r);}
			}
		}
		return true;
	}
	/*{
		if(r11.inside(x,y) && okSquare(1,1))
			swap(1,1);
		else if(r12.inside(x,y) && okSquare(1,2))
			swap(1,2);
		else if(r13.inside(x,y) && okSquare(1,3))
			swap(1,3);
		else if(r14.inside(x,y) && okSquare(1,4))
			swap(1,4);
		else if(r21.inside(x,y) && okSquare(2,1))
			swap(2,1);
		else if(r22.inside(x,y) && okSquare(2,2))
			swap(2,2);
		else if(r23.inside(x,y) && okSquare(2,3))
			swap(2,3);
		else if(r24.inside(x,y) && okSquare(2,4))
			swap(2,4);
		else if(r31.inside(x,y) && okSquare(3,1))
			swap(3,1);
		else if(r32.inside(x,y) && okSquare(3,2))
			swap(3,2);
		else if(r33.inside(x,y) && okSquare(3,3))
			swap(3,3);
		else if(r34.inside(x,y) && okSquare(3,4))
			swap(3,4);
		else if(r41.inside(x,y) && okSquare(4,1))
			swap(4,1);
		else if(r42.inside(x,y) && okSquare(4,2))
			swap(4,2);
		else if(r43.inside(x,y) && okSquare(4,3))
			swap(4,3);
		else if(r44.inside(x,y) && okSquare(4,4))
			swap(4,4);
		return true;
	}*/
 
 
	public boolean okSquare(int r, int c)
	{
		boolean temp = false;
		if (matrix[r-1][c].equals("Y"))
			temp = true;
		else if (matrix[r+1][c].equals("Y"))
			temp = true;
		else if (matrix[r][c-1].equals("Y"))
			temp = true;
		else if (matrix[r][c+1].equals("Y"))
			temp = true;
		return temp;
	}
 
 
	public void swap(int r, int c)
	{
		matrix[blankR][blankC] = matrix[r][c];
		matrix[r][c] = "Y";
		blankR = r;
		blankC = c;
		repaint();
	}
 
 
	public void update(Graphics g)
	{
		paint(g);
	}
 
 
}