DateTime format problem when passing in as Sql Parameter.

OK, I have a stored procedure that accepts parameters and one of which is of SqlTYpe DateTime (default and unchangable size of 8). Now, I am passing in the value, via a function that I created and I have to do it like this as it is a requirement.
THe problem is that when i pass in the datetime as a string, when it converts it to string and executes the query, i get the following error:

String was not recognized as a valid DateTime.

I debugged the code and the value for the string is exactly what it shud be, i.e. 14/9/2004
For your convenience, here is the function that i use...!!

public void UpdateHasTaken(int moduleID, string PackDescription, string StudentNo, string ReservedOn)
            {
                  // Create Instance of Connection and Command Object
                  SqlConnection myConnection = PortalSettings.SqlConnectionString;
                  SqlCommand myCommand = new
                        SqlCommand("RMIT_DesignStore_UpdateHasTaken", myConnection);

                  // Mark the Command as a SPROC
                  myCommand.CommandType = CommandType.StoredProcedure;
                  // Add Parameters to SPROC
                  SqlParameter parameterModuleID = new SqlParameter("@ModuleID",
                                                                                                                 SqlDbType.Int, 4);
                  parameterModuleID.Value = moduleID;
                  myCommand.Parameters.Add(parameterModuleID);

                  SqlParameter parameterPackDescription = new SqlParameter("@PackDescription",
                                                                                               SqlDbType.NVarChar, 50);
                  parameterPackDescription.Value = PackDescription;
                  myCommand.Parameters.Add(parameterPackDescription);

                  SqlParameter parameterStudentNo = new SqlParameter("@StudentNo",
                                                                                                  SqlDbType.NVarChar, 8);
                  parameterStudentNo.Value = StudentNo;
                  myCommand.Parameters.Add(parameterStudentNo);

                  SqlParameter parameterReservedOn = new SqlParameter("@ReservedOn",                    
                                                                                                  SqlDbType.DateTime, 8);
                  parameterReservedOn.Value = ReservedOn;
                  myCommand.Parameters.Add(parameterReservedOn);

                  myConnection.Open();
                  myCommand.ExecuteNonQuery();
                  myConnection.Close();
            }

Is there a formatting problem ? The date passed in as a string is of format dd/mm/yyyy.
If you could help me with this, that would be great.

Thanks