Permission to obtain SVGDocument.getElementById property denied

Hello i am trying to make an application where i can control an SVG image from another browser window. The communication between windows is ok, and my receiver gets the info, but when i try to access to the SVG file to change something firebug tells me that i don't have permission to acess the svg file:S

to simplify, my SVG file is embebed like this:

<embed id="car1" height="100" width="500" pluginspace="http://www.adobe.com/svg/viewer/install/" type="image/svg+xml" src="car1_5.svg" name="car1"/>

And the way i test the access to it:

window.onload = function()
{
svgdoc = document.car1.getSVGDocument();
var door = svgdoc.getElementById("door1");
door.setAttribute("stroke-opacity",0.4);
}

What is strange is that it lets me get the SVG document... but then i can't access to the "door", wich is an element of the SVG.

Ah... and i don't have any problem with IE... it works fine there:S Can anybody help me???pleaseeeeee:)

I'm not sure, but did you try object tag instead of embed tag?

<object data="car1_5.svg" id="car1" type="image/svg+xml" width="500" height="100"><a href="http://www.adobe.com/svg/viewer/install/">plugin</a></object>

???