custom element behavior and location within document tree / dom

I have a number of custom behavior elements (combobox.htc for example)
that I create from an htc. They work perfectly, but there is one thing
that annoys me.
I would like to be able to reference them using Form1.myElementID but I
cannot. I have to leave off 'Form1'.

Can someone tell me how to get a custom element to be part of the form?

On the same subject, can someone explain why elements such as TD, TR,
DIV, etc. have the same behavior. (i.e cannot reference them in Form1).

tia,

mike

mszanto@hotmail.com