First of all you should know about flash sms.
A Flash SMS appears directly on the phone's screen, instead of the 'Inbox'. Its an useful alternative to normal SMS when you want to catch the recipients attention immediately. The recipient has the option of 'Saving' the Flash SMS to his 'Inbox' (Depend upon hanset).

I mentioned here for non compatible handset because costly handsets have option to send flash sms.


Sending Flash Message
To send a flash SMS, compose a SMS with these contents:

Flash [recipient number] [message]

and sent it to 58243.
The recipient will receive the flash SMS on his screen. The flash SMS will appear directly on the recipients screen, and not in the 'Inbox'.

Send Blinking Message
To send a flash SMS, compose a SMS with these contents: