How to set background colour of a line?!

Hi folks.

I’m trying to set the background of a createTextField(), BUT only for the lines, not the whole box.

If I use background and backgroundColor, it sets the whole text box bg to be white, but I only want the lines filled in.

For example, if you ‘select’ the text on an HTML page, only the lines are highlighted. Can this be done in Flash? :h:

I’m using CS3 AS2.

thanks!