PL/SQL stored procedure

Here is a procedure that I created. The table has 2 fields name and age. I would like to know how it run it and when I compile it, it gives me errors.

create procedure tst(va in out number,n out varchar2)
as
begin
dbms_output.put_line('Testing...');
dbms_output.put_line('Enter age ');
va:=28;
select name into n from test where age = va;
end;
.
run;
set serveroutput on;
begin
tst;
end;
.



ERROR:

Procedure created.

1 begin
2 tst;
3* end;
tst;
*
ERROR at line 2:
ORA-06550: line 2, column 1:
PLS-00306: wrong number or types of arguments in call to 'TST'
ORA-06550: line 2, column 1:
PL/SQL: Statement ignored


Thanks.

The following worked for me in SQL*Plus:

SQL> create procedure tst(va in out number,n out varchar2)
as
begin
dbms_output.put_line('Testing...');
dbms_output.put_line('Enter age ');
va:=28;

end;

SQL> set serveroutput on

No semi-colon at the end, since it's an SQL*Plus command


SQL> var x number
SQL> var y varchar2
SQL> exec tst(:x,:y);

Testing...
Enter age

PL/SQL procedure successfully completed.

regards,
Dan