filter to body pages

I need to filter only bodypage within this iterator below

anyone know an easy way to do this?

thanks

var doc= app.ActiveDoc;

iterate(doc)

function iterate(doc)

{

        var pgf = doc.FirstPgfInDoc;

       while (pgf.ObjectValid())

    {

/*

     if(bodypage)   

     {

     //do something

     }

*/

        pgf = pgf.NextPgfInDoc;//NextPgfInFlow

}

}