hi to all and tx for your support.
until now to add a custom tab to facebook page i use this url https://www.facebook.com/dialog/pagetab?app_id=APP-ID&redirect_uri=APP-URL
in this way i add correctly the Secure Page Tab URL to my facebook page.
my problem is that i need to add different tabs related to different urls inside the same application. i need to add for example a tab called "CONTACT" related to APP-URL/contact, another tab called "PRODUCTS" related to APP-URL/products and so on. i don't want create more than one facebook application to do this, is it possibile?
That is impossible, you can´t install an App more than one time per Page. You can only show different content depending on the Page by reading the Page ID in the signed_request parameter.
In other words: One App can be installed on several Pages, but one App can only be installed one time per Page.
Information about how to use the signed_request parameter can be found in many Stackoverflow threads, for example: how to read facebook signed_request to get user_id
It´s a simple POST parameter and you need to parse it. Just debug the result and you will see the Page ID.