 <p>You reference the host control with the <code>outerDocument</code> property... so you would call <code>outerDocument.DP_PRAT_INIT</code> if you want to access that array. BUT, that array is private, so you have to make it public. Or, you can make a public function that you can call on <code>outerDocument</code> but ... yuck.</p> <p>If I am understanding your code properly, you should access the <code>data</code> property of the <code>GridItemRenderer</code> which is the same as <code>outerDocument.DP_PRAT_INIT[ddlTuVous.selectedIndex]</code> except that it is better because you don't have possible index mismatches...</p> <p>So, what you really want is:</p> <pre><code>data.prTuVous = ddlTuVous.selectedItem; </code></pre>