JavaScript and iFrame

Hallo,

i integrate a non Vaadin-Application in my Vaadin Application. I use a Iframe.
The non Vaadin-Application integrates JavaScript Funktions. Here "toAlert()". 

I want to click a Vaadin Button and then the JavaScript Funktion toAlert() in the Iframe is called.
 
Here is my code:

txtHtml.setContentMode(ContentMode.HTML);
      txtHtml.setValue("<iframe id='MapFrame' style='width:100%;height:500px;' src='http://localhost:8081/map/map_openlayers_test.html'></iframe>");
      
      
      cmdManipulateJavaScript.setCaption("JavaScript call");
      cmdManipulateJavaScript.addClickListener(new Button.ClickListener() {
            
            private static final long serialVersionUID = 1L;

            @Override
            public void buttonClick(ClickEvent event) {
                Page.getCurrent().getJavaScript().execute("window.frames[0].toAlert();");
                
            }
        });

This code only run in MicrosoftInternetExplorer not in Firefox or Chrome.

How I solve this Problem. 
How I call JavaScript code locally on Clint-Side.

Thanks
Patrick

I beliewe window.frames is an IE feature, but this link has code that should work in all browsers:
http://stackoverflow.com/questions/251420/invoking-javascript-code-in-an-iframe-from-the-parent-page

Hallo Thomas,

that was a great tip.

I solved this Problem with:

private Label txtHtml;
...
txtHtml.setContentMode(ContentMode.HTML);
txtHtml.setValue("<iframe [color=#FF0000]id='KartenFrame' name='KartenFrame'[/color] scrolling='no' style='width:96%;height:500px' src='http://localhost:8080/map/map_openlayers_test.html'></iframe>");

Thanks
Patrick