Mdi parent - Children relations

Question

Can I access the MdiParent elements from its child being called?

ie:

parent :

public int a=0;

parent_Load()

{

child.MdiParent=this;

child.show();

}

Child :

button1_Click()

{

parent p=new parent();

p.a=1;

this.close();

}

but the problem is; when the focus returns to parent, the value of a remains the same(0).

pls help...