执行sql脚本时出错！

SET DEFINE ON;
DEFINE name = Gaurav
DEFINE today =10/10/2011 --variable that contain date value.

@userdata.sql
DECLARE 
v_date DATE;
v_name varchar2(10);
BEGIN
v_date:=\'&today\';
v_name:=\'&name\';
dbms_output.put_line(\'name is \'||v_name);
dbms_output.put_line(\'date is \'||v_date);
end;

v_date:=\'&today\';

v_date:=to_date(\'&today\',\'DD/MM/YYYY\');