Having trouble on sd open photo name (AT command) (GSM module- SIM900)

The program i have, the "Instant_filename" is cha format, and it changed when i took a new photo FROM CAMERA I CONNECTED TO ARDUINO BOARD,e.g photo001.jpg,photo002.jpg....... BUT THE PROBLEM I HAVE,IS I CANT SEND THE PHOTO,IT TELL ME "NO CONTENT IN THE BUFFER, SO I THINK "Serial2.print(Instant_filename);" & "dataFile=SD.open("Instant_filename");", THEIR NAME DOESNT MATCH.
Serial2.print("AT+CMMSDOWN="PIC",5000,2000000,");
Serial2.print(""");
Serial2.print(Instant_filename);
Serial2.print(""");
Serial2.print("\r");
if(Serial2.available())
{
while(Serial2.available()) Serial.write(Serial2.read());
}

dataFile=SD.open("Instant_filename");
i=0;
if(dataFile)
{
while(dataFile.available())
{
data=dataFile.read();
if(data<0x10) Serial.print("0");
Serial.print(data,HEX);
i++;
if((i%40)==0) Serial.println();
Serial2.write(data);
}
dataFile.close();
}
else
{
Serial.println("error opening Instant_filename");
}

The original program i saw it on web for my reference.
Serial2.print("AT+CMMSDOWN="PIC",19293,2000000,"test.jpg"\r");
delay(1000);
if(Serial2.available())
{
while(Serial2.available()) Serial.write(Serial2.read());
}

dataFile=SD.open("test.jpg");
i=0;
if(dataFile)
{
while(dataFile.available())
{
data=dataFile.read();
if(data<0x10) Serial.print("0");
Serial.print(data,HEX);
i++;
if((i%40)==0) Serial.println();
Serial2.write(data);
}
dataFile.close();
}
else
{
Serial.println("error opening test.jpg");
}

We can not tell what the problem is with just a snippet of code.

The SD library that comes with the IDE allows for names of files in the 8.3 format EXCLUSIVELY.