Alternating row colors using css

Hi,

I am trying to alternate row colors of my grid. I was using the following scripts, however, none of them are working. Maybe someone has a script that is working:

Code 1:

<style type="text/css">
#[% QuestionName() %]_row .alt_color1
{
	background-color: #C7C7C7;
}
#[% QuestionName() %]_row .alt_color2
{
	background-color: #EBEBEB;
}
</style>

<style type="text/css">
.grid .row .alt_color1
{
	background-color: #C7C7C7;
}
.grid .row .alt_color2
{
	background-color: #EBEBEB;
}
</style>