How to Rollback a Dropped Table

Hi

How i do i rollback from a dropped table?

I have created a sample table as follows

begin transaction

create table sample_t1
(id int,
class nvarchar(100),
subject nvarchar(100))

INSERT INTO sample_t1 VALUES(10,'XYZ','LKJ')
INSERT INTO sample_t1 VALUES(10,'XYZ','LKJ')
INSERT INTO sample_t1 VALUES(10,'XYZ','LKJ')
INSERT INTO sample_t1 VALUES(10,'XYZ','LKJ')
INSERT INTO sample_t1 VALUES(10,'XYZ','LKJ')

SELECT * FROM sample_t1

DROP TABLE sample_t1

ROLLBACK ----> "when this command is issued, it says commands compelted successfully in the message area , but when i check through select * from sample_t1, it says " invalid object name sample_t1"

Please help