send sms to client

hello to all.. I am making the project as coding in c# and designing in silver light3..

As you all know that there is a site named waystosms.com via lot of

sms can be send

the same I want to give the facility to the client in my software that whenever the client click on the button "send sms", the sms should be sent..

In the designing part i have done

1.) Mobile number ---- client's mobile no.

2.) Message ------

3.) sender ID ---

and the button send sms

plz help me

Now what coding is required

thanks in advance