how to take input from mic in channel in DSK6713?

hello everyone

i am trying to get input mic in channel which is connected with microphone...and trying to watch it on CRO...

i have successfully  done process of taking input from line in channel which is connected with function generator and output from line out channel which is connected with CRO.....

i am just taking input from ADC and giving it directly to DAC without any process on input signal...just to check that everything works fine or not....

my programme is given below which i am using for mic in input or to take input from microphone.....

#include "dsk6713_aic23.h"                                             //codec-DSK support file
Uint32 fs=DSK6713_AIC23_FREQ_8KHZ;                   //set sampling rate
#define DSK6713_AIC23_INPUT_MIC 0x0015
#define DSK6713_AIC23_INPUT_LINE 0x0011
Uint16 inputsource=DSK6713_AIC23_INPUT_MIC;

interrupt void c_int11()                                                      //interrupt service routine
{
short sample_data;
sample_data = input_left_sample(); //input data
output_sample(sample_data); //output data
return;
}
void main()
{
comm_intr();                                                                    //init DSK, codec, McBSP
while(1);                                                                           //infinite loop
}

i am following rulph chassaing's book for programming of TMS320C6713......

suggest me any changes that i should do to take i/p from mic in.....

regards 

jay sompura