I'm trying to open a window and scroll down "a little" in the newly opened window.

function createPop(url, name)
{
  var newwindow;  
  newwindow=window.open(url,name,'width=760,height=950,toolbar=0,menubar=0,location=0,popup=1,status=0');
  if (window.focus) {newwindow.focus()}

  newwindow.scrollBy(0,400);
}

A new window opens, but scrolling doesn't working. I tried many different ways (scrollTo ...), but nothing changed. What is wrong?