Why I Can't Send SMS.
To send and receive SMS (also called as text messages) you must have the mobile phone with the SMS service enabled form your mobile phone service provider.
Some time your mobile phone service provider enabled your service and your SMS sending or receiving facility still not working. In this case you must contact the service provider or carrier to give you their sms service centre number. You must add it and enable the service.
May be you don't have enough funds to use the text message service.
May be the area where you are standing may not have the signal coverage from your carrier or mobile phone service provider.
Check whether you have enough battery power to operate your mobile phone.
May be the receiving person's mobile phone is not in the "ON" position.
May be the receiving person's mobile phone is not in the area where signal or coverage is available.
May be the receiving person's mobile phone is not in service with any mobile phone service provider or carrier.
Here you can read how to enable the Message Centre.
Go to the Menu in the mobile phone.
select MESSAGES
Select WRITE MESSAGES
Select SETTINGS
Select SERVICE CENTRE NUMBER
Write the number (For Sri Lanka Dialog it will be like this +9477000003)
Accept or OK
If done exit and you are ready to use the sms service.