Creating Bill Program

//class buuldin g with set and get type command and
//use of Default Constructor
public class Bill{
private int bno;
private int bamt;
public Bill(){
bno=20;
bamt=3200;
}
public void setBillNo(int i){
if(i>0 && i<1000){
bno=i;
}else{
System.out.println("invalid Bill Number");
}
}public void getBillNo(){
System.out.println("Bill No. : \t"+bno);
}
public void setBillAmt(int i){
if(i>500 && i<5000){
bamt=i;
}
else{
System.out.println("Invalide Amount");
}
}
public void getBillAmt(){
System.out.println("Bill Amount : \t"+bamt);
}
public static void main(String args[]){
Bill b1=new Bill(),b2=new Bill();
b2.getBillNo();
b2.getBillAmt();
b1.setBillNo(54);
b1.getBillNo();
b1.setBillAmt(4000);
b1.getBillAmt();
}
}