Seeedstudio SIM900 Arduino GPRS Shield V2.0 does not reply response to terminal

I have Arduino Leonardo and Seeedstudio GPRS Shield v2.0 (http://www.seeedstudio.com/wiki/GPRS_Shield_V2.0). Both of them working seamlessly. Following tutorial on main gprs shield link here http://www.seeedstudio.com/wiki/GPRS_Shield_V2.0, I’ve succesfully compiled the following code to arduino:

#include <SoftwareSerial.h>


SoftwareSerial GPRS(7, 8);
unsigned char buffer[64]; // buffer array for data recieve over serial port
int count=0;              // counter for buffer array 
void setup()
{
  GPRS.begin(19200);      // the GPRS baud rate   
  Serial.begin(19200);    // the Serial port of Arduino baud rate.

}

void loop()
{
  if (GPRS.available())            // if date is comming from softwareserial port ==> data is comming from gprs shield
   {
    while(GPRS.available())        // reading data into char array 
    {
      buffer[count++]=GPRS.read(); // writing data into array
      if(count == 64)break;
  }
    Serial.write(buffer,count);    // if no data transmission ends, write buffer to hardware serial port
    clearBufferArray();            // call clearBufferArray function to clear the storaged data from the array
    count = 0;                     // set counter of while loop to zero
  }
  if (Serial.available())          // if data is available on hardwareserial port ==> data is comming from PC or notebook
    GPRS.write(Serial.read());     // write it to the GPRS shield
 }
void clearBufferArray()            // function to clear buffer array
{
  for (int i=0; i<count;i++)
     { buffer[i]=NULL;}            // clear all index of array with command NULL
}

the code above takes AT Command from serial as input and pass it to gprs module. So, I could type something like: “ATD + +1XXXXXXXX” which code to call numbers, and it worked. The problem is I can’t get response from gprs module serial, it’s just blank. I read that the right response to serial terminal should be: “OK”. My questions are:

a. Is there something I missed? I want to get response written to the terminal.

b. I want to make http request, does someone has experience how to do it? What I mean is this gprs opening website blablablabla.com/cs/blabla.php?name=blabla

thx before

b. I want to make http request, does someone has experience how to do it? What I mean is this gprs opening website blablablabla.com/cs/blabla.php?name=blabla

Maybe this will give you a very good way of testing it:
http://m2msupport.net/m2msupport/module-tester/