to the callback routine; it gives you a way to pass data to the callback; in our example, we pass the record handle in the buffer), and a pointer to a callback function. The callback function is passed a <CODE>
FieldHeader</CODE>
 structure and a pointer to the data buffer that was passed to<CODE>
 FoamDBFieldEnum()</CODE>
. From the FieldHeader, it can get the <CODE>
FieldID</CODE>
 from the <CODE>
FieldHeader</CODE>
's <CODE>
FH_id</CODE>
 field. To get information about each field, use the <CODE>
FoamDBG