Java - making our own Exception class

Here I have created Bank, account classes and an exception class of InsufficientFundsException

Bank.java

public class Bank {
    Account acct;
    String name;
    Bank(String name){
        this.name = name;
    }

    /**
     * @param args
     */
    public static void main(String[] args){
        // TODO Auto-generated method stub
        Bank bank = new Bank("SBI");
        bank.acct=new Account(656565656);
        System.out.println("depositing 500");
        bank.acct.deposit(500);
        System.out.println("withdrawing 300");
        try{
        bank.acct.withdraw(300);
        }
        catch(InsufficientFundException e){
            //e.printStackTrace();
            System.out.println(e.getMessage());
        }
        //System.out.println(bank.acct.bal);
        System.out.println("again withdrawing 300");

    }
    public void makeWithdraw(int amt){
        try{
        acct.withdraw(amt);
        }
        catch(InsufficientFundException e){
            System.out.println(e.getMessage());
        }
    }

}
class Account{
    long acctNo;
    int bal;
    Account(long an){
        acctNo = an;
    }
    public void deposit(int amt){
        bal +=amt;
    }
    public void withdraw(int amt) throws InsufficientFundException {
        if(amt<=bal){
            bal -=amt;
        }
        else{
            throw new InsufficientFundException("Not enough balance, balance is "+bal);
        }
    }
}

InsufficientFundException

public class InsufficientFundException extends Exception {
    public InsufficientFundException(String str){
        super(str);
    }
}