ethernet shield + gsm/gprs sim900 modules

Hello! I use sim900 modules and ethernet shield to send sms to my server. I use code like:

IPAddress server(111,111,111,111); 
int send_sms_status = 2;

EthernetClient client;

void setup() {
  
  Serial.begin(9600);
  while (!Serial) {
    ; // wait for serial port to connect. Needed for Leonardo only
  }
  
   pinMode(SEND_LED, OUTPUT);
  
   Serial.println("SMS Messages Sender");


  // connection state
  boolean notConnected = true;
  
  while(notConnected)
  {
    if(gsmAccess.begin(PINNUMBER)==GSM_READY)
      notConnected = false;
    else
    {
      Serial.println("Not connected");
      delay(1000);
    }
  }
  
  Serial.println("GSM initialized");
  
  if (notConnected==false)
  {
 Serial.println("\nCOMPLETE!\n");
  }

    
      // start the Ethernet connection:
  if (Ethernet.begin(mac) == 0) {
    Serial.println("Failed to configure Ethernet using DHCP");
    // no point in carrying on, so do nothing forevermore:
    for(;;)
      ;
  }
  
  delay(1000);
  
      Serial.print("My IP address: ");
    
      for (byte thisByte = 0; thisByte < 4; thisByte++) {
        Serial.print(Ethernet.localIP()[thisByte], DEC);
        Serial.print("."); 
      }
      Serial.println();
  
}

void loop () {
 
  
  char c;
  
  Serial.println("Wait for sms...");
  Serial.println(GetSms);
  
  if (GetSms==true)
{ 
  blink_diod (GET_SMS_LED, 400);
}
  
  
  if (sms.available())
  {
   
    GetSms = true;
    
    // Get remote number
    sms.remoteNumber(senderNumber, 20);


    // An example of message disposal    
    // Any messages starting with # should be discarded
    if(sms.peek()=='#')
    {
      Serial.println("Discarded SMS");
      sms.flush();
    }
    
  //  analogWrite(LED, 250); 
    int o = 0; 
    // Read message bytes and print them
    while(c=sms.read())
    {
     // Serial.print(c);
     
      sms_text [o] = c;    
      o++;
      
    } 
    Serial.println("\nEND OF MESSAGE");
    
    // Delete message from modem memory
    sms.flush();
    Serial.println("MESSAGE DELETED");
    
    Serial.println("Message received from:");
    Serial.println(senderNumber);
    
    Serial.println("With text:");
    Serial.println(sms_text);
    
   SmsText = sms_text;
   TelNum = senderNumber;

 //connectToServer("dfdf", "555");
 
 
 Serial.println("connecting...");

send_sms_status = 1;

  if (client.connect(server, 80)) 
  {
    Serial.println("connected");
        
    PrevMillForSend = millis();
    
  start_send_serv = true;  
  
  String temp = "data=5";
  
           
           Serial.println("Sending to Server: ");                    
client.println("POST /get_sms.php HTTP/1.1");
Serial.print("POST /get_sms.php HTTP/1.1");           
client.println("Host: mysite.com");
//client.print("Content-Length: ");
//client.println(temp.length());
client.println();
client.print(temp);
client.println();

    
     }   
  else 
    Serial.println("connection failed");
 
    
  }
  
  delay(1000);
  

}

When i use only this code all is okey: i get message:“SMS Messages Sender”, “GSM initialized”… and get “My IP address:” and every second get “Wait for sms…” but on my server side i have

empty POST header.

I understand that it’s happened because the lines

//client.print("Content-Length: ");
//client.println(temp.length());

are commented

BUT if i uncomment i have only “SMS Messages Sender” and nothing more…

Maybe someone knows what could be the problem? I would be very grateful for the help!!!