Generating auto incremented field

[Hussein Baghdadi]

Hi all.
I have JBoss 3.2.5 and MySQL 4.0
my entity bean has an auto generated field.
I know how to create an auto generated field in MySQL but how to make this in JBoss ?
I mean, which of JBoss specific deployment files this attribute should occure ?
what is its syntax ??
another question :
this entity bean has a method called : getProcudtID( )
should I declare a cmp-field element in ejb-jar.xml file like this :
<cmp-field><filed-name>productID</field-name></cmp-field>
thanks.