[Indesign] get a paragraph's index within it's parent textframe

gistfile1.js

if (!Array.prototype.indexOf) {
    Array.prototype.indexOf = function (item, i) {
        i || (i = 0);
        var length = this.length;
        if (i < 0) i = length + i;
        for (; i < length; i++)
        if (this[i] === item) return i;
        return -1;
    }
}

var p = app.selection[0],
    inxs = p.parentTextFrames[0].paragraphs.everyItem().index,
    inx = p.index;
alert(inxs.indexOf(inx) + 1);