Passing clobs to sp

Hi to everybody,

I was having problems with my triggers with long datatypes and I converted them in clobs.Every thing ok with triggers but now I am trying to make a stored procedure which has an in parameter of type clob.When I try to test the sp I get the following error:

ORA-06550: line 3, column 44:
PLS-00382: expression is of wrong type
ORA-06550: line 3, column 12:
PL/SQL: Item ignored
ORA-06550: line 12, column 49:
PLS-00320: the declaration of the type of this expression is incomplete or
malformed
ORA-06550: line 11, column 3:
PL/SQL: SQL Statement ignored

The sp simply inserts some data into the table.
What can I do?

Thanks