drop down menu going behind iframe containing pdf

I am having trouble getting my drop down navigation menu infront of iframe in IE. My drop down menu is going behind the iframe where I am loading 开发者_JS百科pdf. I tried z-index, wmode, alpha transparency but none of that worked. Is it possible to get drop down menu infront of iframe containing pdf?

drop-downs are major pains in IE- esp in IE6 and with flash. You might need to absolutely place the elements on the page. The ones you specify first will appear above the others.