Doubt

Hello all,

I am new to this group and so might be asking a question which 
might ahve already been answered, or is very simple.Sorry for 
that.

If we have to make a DTD for a database with 2 tables, say A and 
B.The attributes of the tables are as under:


Table A
A.1(PRIMARY KEY)
A.2
A.3(FORIEGN KEY TO TABLE B)

Table B
B.1(PRIMARY KEY)
B.2(foriegn key to table A)

Now can anyone guide me on how to write a simple DTD for 
this.Means , do we have to declare a content type declaration for 
the forign keys also??IF not then how do we write the XML document 
for this?

secondly How to impose the many-to-many and one-to-many 
relationships?

Thanks
Mudita