[flexcoders] Creating style for AdvancedDataGridColumn that dded dynamically

[yossi.baram]

Hi,
I have an AdvancedDataGrid and I add its  columns dynamically(with new 
instanciate).
I created a css file and I control the DataGrid, but for the columns it doesnt 
respond, why? 

/* CSS file */
AdvancedDataGrid
{
  verticalGridLines: true;
  horizontalGridLines: true;
  border-style: none;
  selectionColor: #a2c2e4;
  rollOverColor: #FFFFFF;
  alternating-item-colors: #F4FBFF, #FFFFFF;
}
AdvancedDataGridColumn
{
  textAlign:left;
}

Is it because the columns were created dynamically? and not as Flex tags?

I need all the styles to be added inside a css file.

oh, one small qestion if I may:
How can I eliminate the blue background sorounding the grid?
(I created the grid as a Tag and I need to plant it inside a page but without 
the background).

Please advice on both issues if you can...

Thanks  a lot
Jo