get current tabIndex value for document with javascript

I have a custom d开发者_运维百科rop down box I have made and focus can be brought into with the tab key automatically, but I can not pass focus to the next element in line...how do I do this?

I was thinking getting the current value of what the current 'tabIndex' is and setting focus to the next in line, any other way? Using mootools btw

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Old questions, let me share how I solved the problem.

I stashed a text input behind my custom control that actually receives the focus. This way I use it not also to catch text to search the dropdown.