--------------------------------This is my parent class---------------------------------

public class Item
{
private int _ITEM_ID;
private string _Name;
private string _Description;
private ISet bids = new HashedSet();

public virtual ISet Bids
{
get { return bids; }
set { bids = value; }
}
public virtual void addBid(Bid bid)
{
bid.itemvar = this;
bids.Add(bid);
}
}


<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" assembly="DTO" namespace="Business.Entities">
<class name="Business.Entities.Item" table="ITEM">

<id name="ITEM_ID" column="ITEM_ID" type="Int32" unsaved-value="null">
<generator class="native"/>
</id>
<set name="Bids" inverse="true" cascade="all-delete-orphan">
<key column="ITEM_ID"></key>
<one-to-many class="Bid"/>
</set>
<property column="Name" type="string" name="Name" />
<property column="Description" type="string" name="Description" />
</class>
</hibernate-mapping>

-----------------------------------------This is my child class-----------------------------------


public class Bid
{
private int _BID_ID;
private int _Amount;
private int _ITEM_ID;
private Item _itemvar;
}

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" assembly="DTO" namespace="Business.Entities">
<class name="Business.Entities.Bid" table="BID">

<id name="BID_ID" column="BID_ID" type="Int32" unsaved-value="null">
<generator class="native"/>
</id>
<many-to-one name="itemvar" column="ITEM_ID" class="Item" not-null="false">
</many-to-one>

<property column="Amount" type="int" name="Amount" />
</class>
</hibernate-mapping>

---------------This is where i am calling my methods to save data in to child-------------------------



Bid bid = new Bid();
bid.Amount = 100;

Item item = new Item();
item.Name = "jewlry";
item.Description = "Its kool man";

item.addBid(bid);

DAL.DAL pub = new DAL.DAL();
pub.addItems(item);




public void addBids(Bid bid)
{
try
{
session.Save(bid);
session.Flush();
}
catch (Exception ex)
{
throw ex;
}
}




Can any body Tell me how to Fix this... i tried my best at net and book but didn't find ans... i can insert values in Parent.. but cant insert value in Child... its putting null there... ANY Solution will be greatly appreciated