totally a newbie in sending phone number to a webserver

I registered a SMS web service and I have username and password and there are methods as follow which I can use: balance receive send send to all send advanced status status advanced suppose I have a form and I will get the phone number from user also I have user name,pass and url of the web service like $phone['number'],$user,$pass,$url I don't know what exactly I should do to force the php code read from the functions of the web service does including the url enough? I am totally mixed up. can someone tell me what is happening in this procedure? is there any tutorial so that I can understand it? I tried to use sample codes but they were different from which I wanted. Thanks in Advance.