Post using at commands http in sim900b

Hi,

I need to do a POST to a web server I need send information, with a gprs connection and the SIM900B module.

This is the information that I need to send, but when I try to do it, I always get an ERROR.

percepcion=<envEstacion><idEstacion>1</idEstacion><fecha>2013-06-10 17:04:20.683 CDT</fecha><mediciones><medSensor><idSensor>1</idSensor><valor>35.0</valor></medSensor></mediciones></envEstacion>

Can you tell me please what I am doing wrong?

Thank you.



at
OK
at+sapbr=3,1,"contype","gprs"
OK
at+sapbr=3,1,"apn","internet.xxxxx.xxx"
OK
at+sapbr=3,1,"user","xxxxx"
OK
at+sapbr=3,1,"pwd","xxxx"
OK
at+sapbr=1,1
OK
at+httpinit
OK
at+httppara="cid",1
OK
at+httppara="url","www.xxxxxxx.com/xxx/xxxxx/"
OK
at+httpdata=195,10000
DOWNLOAD
ERROR

you must post complete HTTP Post method data.
POST /test/demo_form.asp HTTP/1.1 -> /test/demo_form.asp change this with your url
Host: w3schools.com -> w3schools.com change this with yout hosting name or address
name1=value1&name2=value2 -> this is your parameter value