Scripting for different numbers of table rows in cs3

Interesting ... I don't think there is a newbie-level answer to this challenge. It comes down to finding the first (left-to-right) cell that contains text, and adding a line on top of it all the way to the last cell in that row.

Here's a first attempt:

table = app.selection[0];
if (table.hasOwnProperty("baseline"))
 table = table.parent;
if (table instanceof Cell)
 table = table.parent;
if (table instanceof Column)
 table = table.parent;
if (table instanceof Row)
 table = table.parent;
if (table instanceof Table)
{
 table.cells.everyItem().properties = {topEdgeStrokeWeight:0, bottomEdgeStrokeWeight:0, leftEdgeStrokeWeight:0, rightEdgeStrokeWeight:0};
 table.rows.lastItem().bottomEdgeStrokeWeight = 1;
 for (r=0; r<table.rows.length; r++)
 {
  for (c=0; c<table.rows.cells.length; c++)
  {
   if (table.rows.cells.contents)
   {
    for (; c<table.rows.cells.length; c++)
     table.rows.cells.topEdgeStrokeWeight = 1;
    break;
   }
  }
 }
} else
 alert ("You were supposed to be somewhere inside a Table");