Fit Iframe content with the size

I created a Facebook application to add tabs for pages, the user give me the link of the hosted content shown in the page tab.

this is an example of a tab added by my application.

I want the full URL content to be shown in the page tab frame, Facebook 开发者_StackOverflowtab properties : Max Width : 520px Max Heigth : 800px

Is there any method to reduce the percent of the width + height of the iframe, if the content is don't fit with the size ?

Sorry for my bad english, and thanks in advance.

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If I understand you correctly; you might have success reading over the Facebook's JavaScript SDK, particularly FB.Canvas.setSize() and FB.Canvas.setAutoGrow().