Indeed, $form_state['values'][data1_checkbox] would be where to find the value (0 or 1). Your submit function should be formed like:

function test_myform_submit($form, &$form_state)

Nancy

Injustice anywhere is a threat to justice everywhere. -- Dr. Martin L. King, Jr.

From: "Kim, Soonho (IFPRI)"
I have a problem to find a checkbox value in a form.
I guess that I might get the value from " $form_state['values'][data1_checkbox] " but I don't know how to get the $form_state from $form..