[wig]

go to this websit :
http://www.callwave.com/sms/sms.asp
download Google Gadget or yahoo widget (main engine should be installed your computer) of callwave and run it.
It will look like this:
in the left lower corner there is an icon i click on it and give some info..(not necessarily correct ) then in the Number field give recipent mobile number (i.e 880171xxxxxxx) and select Mode as International Then type ur message and send it

there are other site to send free sms like :
sms.ac -> 20 free sms per month, max 3 a day
playtxt.net -> 5 free sms per month..

good luck