// grab possible SET/ENUM values and return an array
function getPossibleValues($table,$field){
	$query = "SHOW COLUMNS FROM `$table` LIKE '$field'";
	$result = mysql_query($query);

	if(mysql_num_rows($result)>0)
	{
		list(,$fields) = mysql_fetch_row($result);
		$options = explode("','",preg_replace("/(enum|set)('(.+?)')/","\2",$fields));
		return $options;
	}
	else
	{
		return array();
		return false;
	}
}

http://www.jellyandcustard.com/2005/11/23/retrieve-valid-entries-for-a-mysql-enumset-column/

Retrieve valid entries for a MySQL ENUM/SET column

mysql, php

PHP