Direction Property
Indicates whether the Parameter represents an input parameter, an output parameter, an input and an output parameter, or if the parameter is the return value from a stored procedure.
Settings and Return Values
Sets or returns a ParameterDirectionEnum value.
Remarks
Use the Direction property to specify how a parameter is passed to or from a procedure. The Direction property is read/write; this allows you to work with providers that don't return this information or to set this information when you don't want ADO to make an extra call to the provider to retrieve parameter information.
Not all providers can determine the direction of parameters in their stored procedures. In these cases, you must set the Direction property before you execute the query.