function selecciona($dis)
{
	$arr = array('None', 'option 1', 'option 2', 'option 3', 'option 4');
	for($i = 0; $i < count($arr); $i++) 
        {
 	 $selected = ($arr[$i] == $dis) ? 'selected="selected"' : '';
 	 echo "<option value=\"{$arr[$i]}\" {$selected}>{$arr[$i]}</option>\n";
        }
}

dynamically selects a value in a select according to what's already in the DB

Setting a select's selected value

php, forms

PHP