Ora-00904 Error For NDS Dynamic Alter Table Statement

how to play around with NDS dynamic sql and I'm trying to add a column on the fly.Basically the procedure is trying to take a table name, column name, and eventually a data type and adds it to a table.

It works fine without the bind variable for the column name, accepting the table name on the fly.As soon as it tries to use the column name I get an ORA-00904 invalid identifier exception.

Here is the procedure I'm using

CODEcreate or replace
procedure test(tbl_name varchar2, col_name varchar2) IS
qry varchar2(500);
begin

[code]....

Here is how I'm executing it.

CODEexecute test(tbl_name => 'BB_SHOPPER', col_name => 'MEMEBER');