If tabIndex attribute is not defined explicitly, browser will assign according to the order it appears in the HTML.
To get the tabIndex, As you said I loop through the element in particular form and I used following function to find the tabindex
element.getAttribute('tabindex'); which is always returning zero for all the enabled elements in the form and for disabled fields it is returning -1. [ December 28, 2006: Message edited by: Prabhu Venkatachalam ]