unresolved symbol: _Codec_ISR in vector.obj during building ccs 6.1 on lcdk

I have added following files:

AIC3106.h, DSP_Config.h, LCDK_Support_DSP.c, LCDK_Support_DSP.h, link6748.cmd, OMAPL138_defines.h,

tistdtypes.h, vectors.asm, ISRs.c, Startup.c and try_1201.c (my file)

//corresponds to 48 output samples and hence the frequency of the sinusoidal analog output
//waveform is equal to the codec sampling rate (48 kHz) divided by 48, that is 1 kHz.
//sine48_buf_intr.c
#include "DSP_Config.h"   
#define LOOPLENGTH   48
#define BUFLENGTH     256
int16_t  sine_table[LOOPLENGTH] =
{0, 1305, 2588, 3827, 5000, 6088, 7071, 7934, 8660, 9239, 9659, 9914, 10000, 9914, 9659, 9239,
8660, 7934, 7071, 6088, 5000, 3827, 2588, 1305, 0, -1305, -2588, -3827, -5000, -6088, -7071, -7934, -8660, -9239, -9659, -9914, -10000, -9914, -9659, -9239, -8660, -7934, -7071, -6088,
-5000, -3827, -2588, -1305};
int16_t  sine_ptr = 0;                 //pointer into lookup table

interrupt void interrupt4(void)         //interrupt service routine
{
    int16_t    sample;
    sample = sine_table[sine_ptr];        //read sample from table
    output_left_sample(sample);        //output sample
    sine_ptr = (sine_ptr+1)%LOOPLENGTH;    //increment table index
    return;
}

int main()
{    
    // initialize DSP board
      DSP_Init();
    // call StartUp for application specific code
    // defined in each application directory
    StartUp();
    // main stalls here, interrupts drive operation
      while(1);
  }

And also want to know how to change the clock frequency and turn on LEDs and switches on the LCDK board.

Need urgent help.