hi.. i hv few error. pls.

hi sir, i have few error. can u pls help me. pls.
im very new in java. ths my Uni assgmnt.

please help me...

import java.io.*;

public class nathan
{

String title[]={"Biography","Computers","Science","Sports","Religion"};
String author[]={"Francis","Roland","Bobby","Keith","Robbert"};
String publisher[]={"USA","USA","Germany","France","Spain"};
Double price[]={19.00,25.50,20.80,19.60,13.80};
int quantity[]={10,40,32,36,41};
boolean done = false;


public void nathan () throws IOException
{

InputStreamReader input = new InputStreamReader(System.in);
BufferedReader br=new BufferedReader(input);

System.out.println("|!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!|");
System.out.println("| Welcome to |");
System.out.println("| Nathan Book Shop |");
System.out.println(" ------------------------------------------- ");
System.out.println("| 1. All Books |");
System.out.println("| 2. Books By Title |");
System.out.println("| 3. Purchase Books |");
System.out.println("| 4. Exit |");
System.out.println("|~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|");

System.out.println("");
System.out.print("Enter your choice=>");
String op = br.readLine();
int read = Integer.parseInt(op);

switch(read)
{
case 1:

System.out.println("");
allBooks();
break;

case 2:

System.out.println("");
searchTitle();
break;

case 3:

System.out.println("");
purchase();
break;

case 4:

System.out.println("{{{{THANK YOU}}}}");
System.exit(0);
break;

default:

System.out.print("Wrong Info. Please Enter Again");

}
}


public void searchTitle()throws IOException

{
System.out.print("Enter Title Name::");
String name = br.readLine();
int title = Integer.parseInt(op);

switch(title)
{

case "Biography":

System.out.println("\t Title\t\tAuthor\t\tPublisher\tQuantity\tPrice");
System.out.println("\t =============================================");
System.out.println("");
System.out.println("\t "+title[i]+"\t"+author[i]+"\t\t"+publisher[i]+"\t\t"+quantity[i]+"\t\t"+price[i]);
break;


case "Computers":

System.out.println("\t Title\t\tAuthor\t\tPublisher\tQuantity\tPrice");
System.out.println("\t =============================================");
System.out.println("");
System.out.println("\t "+title[i]+"\t"+author[i]+"\t\t"+publisher[i]+"\t\t"+quantity[i]+"\t\t"+price[i]);
break;

case "Science":

System.out.println("\t Title\t\tAuthor\t\tPublisher\tQuantity\tPrice");
System.out.println("\t =============================================");
System.out.println("");
System.out.println("\t "+title[i]+"\t"+author[i]+"\t\t"+publisher[i]+"\t\t"+quantity[i]+"\t\t"+price[i]);
break;

case "Sports":

System.out.println("\t Title\t\tAuthor\t\tPublisher\tQuantity\tPrice");
System.out.println("\t =============================================");
System.out.println("");
System.out.println("\t "+title[i]+"\t"+author[i]+"\t\t"+publisher[i]+"\t\t"+quantity[i]+"\t\t"+price[i]);
break;


case "Religion":

System.out.println("\t Title\t\tAuthor\t\tPublisher\tQuantity\tPrice");
System.out.println("\t =============================================");
System.out.println("");
System.out.println("\t "+title[i]+"\t"+author[i]+"\t\t"+publisher[i]+"\t\t"+quantity[i]+"\t\t"+price[i]);
break;

default:


System.out.print("DIDT FOUND");
}

}

public void purchase()throws IOException
{

System.out.print("Enter book name:");
String name = br.readLine();
int title = Integer.parseInt(op);

switch ("")
{
case 1:

System.out.println("\torder details are as follows:");
System.out.println("\t============================");
System.out.println("");
System.out.println("\tBook title:"+title[i]);
System.out.println("");
System.out.println("\tAuthor:"+author[i]);
System.out.println("");
System.out.println("\tPublisher:"+publisher[i]);
System.out.println("");
System.out.println("\tUnit Price:"+price[i]);
System.out.println("");
System.out.println("\tQuantity:"+qua1);
System.out.println("");
System.out.println("\tTotal:"+total);
System.out.println("");
System.out.print("Thank you");
break;

default:
System.out.print("Book not found");
}

}

public void allBooks()throws IOException
{

System.out.println("Title\t\tAuthor\t\tPublisher\tQuantity\tPrice");
System.out.println("=============================================");
for(int a=0; a<author.length;a++)


{
System.out.println(""+title[a]+"\t"+author[a]+"\t\t|"+publisher[a]+"\t\t|"+quantity[a]+"\t\t|"+price[a]);
System.out.println("");
}

System.out.println("");


}//end of allbooks

public static void main(String args[])throws IOException
{
nathan bk = new nathan();
bk.nathan();
}

}