Finding Child and its property value in the DOM

Thanks for the suggestion :smileyhappy:

I find the solution and tried it directly in Chrome (using native Javascript). It works fine, but unfortunately TC complains that something is not right . 

var CSSselector = "#Detail > div > table > tbody";
Page = Sys.Browser('*').Page("http://www.myweb.com");
aqUtils.Delay(5000);

var par = Page.QuerySelectorAll(CSSselector);
var child2 = par[0].childNodes[1].childNodes[4];
var finish = child2.querySelector('.validate[value]').getAttribute("value");

Then I found that TC doesn't have method childNodes[i] but Child(i). (https://support.smartbear.com/viewarticle/88401/)

Therefore I changed it to 

var child2 = par[0].Child(1).Child(4);

But still TC complains saying "TypeError par[0].Child is not a function".

How to find the n-th child and then the x-th grandchild in TC (and then possible the y-th grand grandchild) and grab it's attribute?  

Thank You.