Option Selection Help

Hello I am new to php and I am having a problem.

I have a form and I would like to know how I go about doing this. I have date field that looks like this:

echo "<TR><TD>Day:</TD><TD><SELECT NAME='day'>\n";
for( $i = 1; $i <= 31; $i++ )
{
echo "<OPTION VALUE='" . $i . "'";
if ( $i == $Day ) echo " SELECTED";
echo ">" . $i . "</OPTION>\n";
}
echo "</SELECT></TD</TR>\n";

I want to populate another field depending on which day it is. What can I do? Do I use javascript saying that if this day is selected do the following? Please help. Thanks.

[CYBER_Aeon]

If your populating it based on the current day, then you can use PHP to do it, just use the $Day check again.

If your doing it based on what they select in the day form field, then you need to use JavaScript.