mssql_fetch_field() can be used in order to obtain information about fields in a certain query result.
resultThe result resource that is being evaluated. This result comes from a call to mssql_query().
field_offset
The numerical field offset. If the field offset is not specified, the
next field that was not yet retrieved by this function is retrieved. The
field_offset starts at 0.
Returns an object containing field information.
The properties of the object are:
name - column name. if the column is a result of a function, this property is set to computed#N, where #N is a serial number.
column_source - the table from which the column was taken
max_length - maximum length of the column
numeric - 1 if the column is numeric
type - the column type.