how to add index on text datatype

[Sanam Shrestha]

code:

CREATE TABLE tbl_message(

message_id int not null auto_increment PRIMARY KEY,

sent_date_time DATETIME not null,

server_ip varchar(32) not null,

sender_name varchar(32) not null,

sender_email varchar(25),

sent_message text not null,

status tinyint(1) not null default 1,

department_id int not null,

INDEX (server_ip, sender_name, sender_email),

FOREIGN KEY (department_id)

REFERENCES tbl_department(department_id) ON UPDATE CASCADE ON DELETE RESTRICT

);

ALTER TABLE tbl_message

ADD INDEX (sent_message);

REPLY ME AS SOON AS POSSIBLE