selectedIndex and row count

Although it seems like there should be an easier way to do this, here's what I came up with.

  <cfinput type="button"
    name="btnEdit"
    value="Edit Line"
    onClick="editLine();" />

...

<script type="text/javascript">

  function getSelectedIndex(grid)
  {
    for (var i=0; i < grid.dataSource.data.items.length; i++)

      if (grid.getSelectionModel().isSelected(i))

        return i;
  }
     
  function editLine()
  {
    var grid = ColdFusion.Grid.getGridObject('gvExhibLines');
    grid.startEditing(getSelectedIndex(grid), 1);
  }

</script>

Still, if there is an easier or more elegant way of accomplishing the same, I would love some feedback.  I'm curious why there isn't a simple grid.selectedIndex.

Also, this line:

  grid.dataSource.data.items.length

returns 15 (which is my grids page size) regardless of how many rows there are in my grid.