Question

Need help in trying to get my java program to work, Its finished but i still have errors left when i compile

WHy do i get this error message"Illegal start of expression void displaysummary() " When i try to complie my java program ?

import java.io.*;
  
public class prog23
{
   public static void main(String[] args) throws I0Exception
   {
       program23 app = new program23();
       app.appMain();
   }
}
class program23
{
  
   BufferedReader stdin;

       int custNum;
       float begBal, overDraft;
       String monthEnd;
      
       int transNum;
       char transType;
       String transDate, overPenalty;
       float transAmt;
      
       float runBal, totCredits, totDebits, totOverAmt;
       int creditTransCtr, lowDebitNum;
       float lowDebitAmt, avgCredit;
      
void appMain() throws I0Exception
{
       reportHeader();
       initReport();
       getAccountInfo();
       initRunningBal();
      
       while (transNum != 0)
       {  
               procTrans();
       }
       calculateAverage();
       displaySummary();
}

void reportHeader()
{

   System.out.print("******************************************\n");
   System.out.println("Program 23 Solution");
  
  
   System.out.println("******************************************\n");
}

void initReport()
{
      
       stdin = new BufferedReader(new InputStreamReader(System.in));
      
       totCredits = 0;
       totDebits = 0;
       creditTransCtr = 0;
       totOverAmt = 0;
       lowDebitAmt = 5001;
       transNum = -11;
}
void getAccountInfo() throws I0Exception
{
       System.out.print("Please enter the account number: ");
       custNum = Integer.parseInt(stdin.readLine());
      
       System.out.print("Please enter the beginning balance for the account: ");
       begBal = Float.parseFloat(stdin.readLine());
      
       System.out.print("Please enter the month end date for this cycle: ");
       monthEnd = stdin.readLine();
      
       System.out.print("Please enter the overdraft penalty amount: ");
       overDraft = Float.parseFloat(stdin.readLine());
}  
      
void initRunningBal()

{
   runBal = begBal;
}

void procTrans() throws I0Exception
{
   getTransNum();
   if (transNum != 0)
   {
           getTransDetails();
           calculateTotalsAndRunBal();
           calculateOverdraftAndPenalty();
           displayTransDetails();
   }
}

void getTransNum() throws I0Exception
{
   System.out.print("\n\nPlease enter the Transaction Number: ");
   transNum = Integer.parseInt(stdin.readLine());
}

void getTransDetails() throws I0Exception
{
       System.out.print("Please enter the Trans Type: ");
       transType = (stdin.readLine().charAt(0));
      
       System.out.print("Please enter the Trans Amount: ");
       transAmt = Float.parseFloat(stdin.readLine());
}

void calculateTotalsAndRunBal()
{
   if (transType == 'C')
   {
           runBal = runBal + transAmt;
           totCredits = totCredits + transAmt;
           creditTransCtr = creditTransCtr + 1;
   }

   if (transType == 'c')
   {
       runBal = runBal + transAmt;
       totCredits = totCredits + transAmt;
       creditTransCtr = creditTransCtr + 1;
   }
  
   if (transType == 'D')
   {
       runBal = runBal - transAmt;
       totDebits = totDebits + transAmt;
       updateLows();
   }
   if (transType == 'd')
   {
           runBal = runBal - transAmt;
           totDebits = totDebits + transAmt;
           updateLows();
   }
}

void calculateOverdraftAndPenalty()
{
   if(runBal < 0)
   {
           runBal = runBal - overDraft;
           totOverAmt = totOverAmt + overDraft;
          
           overPenalty = Float.toString(overDraft);
   {
   else

   {
           overPenalty = "";
   }
}

void updateLows();
{

       if(transAmt < lowDebitAmt)
       {
               lowDebitAmt = transAmt;
               lowDebitNum = transNum;
       }
}

void displayTransDetails();
{
       System.out.println("\n\n\n");
       System.out.println("Customer Transaction:");
       System.out.println( "===========================");
       System.out.println("Transaction #: \t\t" + transNum);
       System.out.println("Transaction Type: \t" + transType);
       System.out.println("Transaction Amt: \t" + transAmt);
       System.out.println("Running Balance: \t" + runBal);
       System.out.println("Over Draft Penalty Amt:\t" + overPenalty);
       System.out.println( "============================");
}

void calculateAverage();
{
       avgCredit = totCredits / creditTransCtr;
}
void displaySummary();
{
       System.out.println("\n\n");
      
       System.out.println("******************************************");  
       System.out.println("****MASCO Monthly Transaction Report Summary****");   
       System.out.println("Customer Account Number: \t\t" + custNum);
       System.out.println("Customer Beginning of Month Balance: \t" + begBal);
       System.out.println("Monthly Transaction Report Ending on: \t" + monthEnd);
       System.out.println("Overdraft Penalty Amount: \t\t" + overDraft);
       System.out.println("******************************************");
       System.out.println("***************************************");
       System.out.println("Customer End Balance:\t" + runBal);
       System.out.println("Total Credits $ Amount:\t" + totCredits);
       System.out.println("Total Debits $ Amount: \t" + totDebits);
       System.out.println("Total Overdraft Amount:\t" + totOverAmt);
       System.out.println("Average Credit Amount: \t" + avgCredit);
       System.out.println();
       System.out.println("Low Debit $ Amount: \t" + lowDebitAmt);
       System.out.println("Low Debit Trans #:\t" + lowDebitNum);
       System.out.println("*******************************");  
       System.out.println("*******************************");  
   }
}