Getting Field Names in Microsoft SQL

I'm trying to build a dynamic script that basically extracts all of the fields in a MS SQL database...I just can't seem to figure out how to get at the field names themselves. I am using the mssql_fetch_array followed by the $row['field_name'] in an array. But I would like to make the field_name dynamic (i.e. not knowing the field_names ahead of time) which would make the script adaptable to any table in the database. So if I get the field's value by $row['field_name'] how do I get at the field's name? thanks, Ron