zIndex of imgAreaSelect jquery library is not working in IE

Is z-i开发者_如何学JAVAndex in CSS is not supported by IE? I'm using the imgAreaSelect jQuery library to select some portion of an image. My code works fine in Chrome and Mozilla but it's not working in IE.

For positioned elements IE6 and IE7 do not support z-index as expected. Use position:relative and z-index:1 for parent element.

http://www.quirksmode.org/bugreports/archives/2006/01/Explorer_z_index_bug.html

http://www.last-child.com/conflicting-z-index-in-ie6/