z-index difficulties

Hello.

I click on a button that loads an html file into a Symbol on Stage.

That is ok.

I have this rectangle is on the stage on top of my Wrapper Symbol that should delete it.

But when the html file loads, I cant see the rect anymore...

This is my code :

// on Click

sym.$("rect").show();

var externalUrl ="print.html";

sym.$("wrapper").html("<iframe src= "+externalUrl+" height=100% width=100% </iframe>");

sym.$("rect").css(z-index:2);

Thanks for any help.

s.