"Failed to open file for reading: in program

I am getting this error “Failed to open file for reading:”
pls clarify why i am getting this error while kernel file and .cpp file is in same project/folder using nvidia GPU ,win 7 64 bit,vs 2010
pls help

HelloWorld.cl
__kernel void hello_kernel(__global const float *a,
__global const float *b,
__global float *result)
{
int gid = get_global_id(0);

result[gid] = a[gid] + b[gid];

}

HelloWorld.cpp

#include <iostream>
#include <fstream>
#include <sstream>
#include <time.h>

#ifdef APPLE
#include <OpenCL/cl.h>
#else
#include <CL/cl.h>
#endif

///
// Constants
//
const int ARRAY_SIZE = 30000;

///
// Create an OpenCL context on the first available platform using
// either a GPU or CPU depending on what is available.
//
cl_context CreateContext()
{
cl_int errNum;
cl_uint numPlatforms;
cl_platform_id firstPlatformId;
cl_context context = NULL;

// First, select an OpenCL platform to run on.  For this example, we
// simply choose the first available platform.  Normally, you would
// query for all available platforms and select the most appropriate one.
errNum = clGetPlatformIDs(1, &firstPlatformId, &numPlatforms);
if (errNum != CL_SUCCESS || numPlatforms &lt;= 0)
{
    std::cerr &lt;&lt; "Failed to find any OpenCL platforms." &lt;&lt; std::endl;
    return NULL;
}

// Next, create an OpenCL context on the platform.  Attempt to
// create a GPU-based context, and if that fails, try to create
// a CPU-based context.
cl_context_properties contextProperties[] =
{
    CL_CONTEXT_PLATFORM,
    (cl_context_properties)firstPlatformId,
    0
};
context = clCreateContextFromType(contextProperties, CL_DEVICE_TYPE_GPU,
                                  NULL, NULL, &errNum);
/*
if (errNum != CL_SUCCESS)
{
    std::cout &lt;&lt; "Could not create GPU context, trying CPU..." &lt;&lt; std::endl;
    context = clCreateContextFromType(contextProperties, CL_DEVICE_TYPE_CPU,
                                      NULL, NULL, &errNum);
    if (errNum != CL_SUCCESS)
    {
        std::cerr &lt;&lt; "Failed to create an OpenCL GPU or CPU context." &lt;&lt; std::endl;
        return NULL;
    }
}*/

return context;

}

///
// Create a command queue on the first device available on the
// context
//
cl_command_queue CreateCommandQueue(cl_context context, cl_device_id *device)
{
cl_int errNum;
cl_device_id *devices;
cl_command_queue commandQueue = NULL;
size_t deviceBufferSize = -1;

// First get the size of the devices buffer
errNum = clGetContextInfo(context, CL_CONTEXT_DEVICES, 0, NULL, &deviceBufferSize);
if (errNum != CL_SUCCESS)
{
    std::cerr &lt;&lt; "Failed call to clGetContextInfo(...,GL_CONTEXT_DEVICES,...)";
    return NULL;
}

if (deviceBufferSize &lt;= 0)
{
    std::cerr &lt;&lt; "No devices available.";
    return NULL;
}

// Allocate memory for the devices buffer
devices = new cl_device_id[deviceBufferSize / sizeof(cl_device_id)];
errNum = clGetContextInfo(context, CL_CONTEXT_DEVICES, deviceBufferSize, devices, NULL);
if (errNum != CL_SUCCESS)
{
    std::cerr &lt;&lt; "Failed to get device IDs";
    return NULL;
}

// In this example, we just choose the first available device.  In a
// real program, you would likely use all available devices or choose
// the highest performance device based on OpenCL device queries
commandQueue = clCreateCommandQueue(context, devices[0], 0, NULL);
if (commandQueue == NULL)
{
    std::cerr &lt;&lt; "Failed to create commandQueue for device 0";
    return NULL;
}

*device = devices[0];
delete [] devices;
return commandQueue;

}

///
// Create an OpenCL program from the kernel source file
//
cl_program CreateProgram(cl_context context, cl_device_id device, const char* fileName)
{
cl_int errNum;
cl_program program;

std::ifstream kernelFile(fileName, std::ios::in);
if (!kernelFile.is_open())
{
    std::cerr &lt;&lt; "Failed to open file for reading: " &lt;&lt; fileName &lt;&lt; std::endl;
    return NULL;
}

std::ostringstream oss;
oss &lt;&lt; kernelFile.rdbuf();

std::string srcStdStr = oss.str();
const char *srcStr = srcStdStr.c_str();
program = clCreateProgramWithSource(context, 1,
                                    (const char**)&srcStr,
                                    NULL, NULL);
if (program == NULL)
{
    std::cerr &lt;&lt; "Failed to create CL program from source." &lt;&lt; std::endl;
    return NULL;
}

errNum = clBuildProgram(program, 0, NULL, NULL, NULL, NULL);
if (errNum != CL_SUCCESS)
{
    // Determine the reason for the error
    char buildLog[16384];
    clGetProgramBuildInfo(program, device, CL_PROGRAM_BUILD_LOG,
                          sizeof(buildLog), buildLog, NULL);

    std::cerr &lt;&lt; "Error in kernel: " &lt;&lt; std::endl;
    std::cerr &lt;&lt; buildLog;
    clReleaseProgram(program);
    return NULL;
}

return program;

}

///
// Create memory objects used as the arguments to the kernel
// The kernel takes three arguments: result (output), a (input),
// and b (input)
//
bool CreateMemObjects(cl_context context, cl_mem memObjects[3],
float *a, float *b)
{
memObjects[0] = clCreateBuffer(context, CL_MEM_READ_ONLY | CL_MEM_COPY_HOST_PTR,
sizeof(float) * ARRAY_SIZE, a, NULL);
memObjects[1] = clCreateBuffer(context, CL_MEM_READ_ONLY | CL_MEM_COPY_HOST_PTR,
sizeof(float) * ARRAY_SIZE, b, NULL);
memObjects[2] = clCreateBuffer(context, CL_MEM_READ_WRITE,
sizeof(float) * ARRAY_SIZE, NULL, NULL);

if (memObjects[0] == NULL || memObjects[1] == NULL || memObjects[2] == NULL)
{
    std::cerr &lt;&lt; "Error creating memory objects." &lt;&lt; std::endl;
    return false;
}

return true;

}

///
// Cleanup any created OpenCL resources
//
void Cleanup(cl_context context, cl_command_queue commandQueue,
cl_program program, cl_kernel kernel, cl_mem memObjects[3])
{
for (int i = 0; i < 3; i++)
{
if (memObjects[i] != 0)
clReleaseMemObject(memObjects[i]);
}
if (commandQueue != 0)
clReleaseCommandQueue(commandQueue);

if (kernel != 0)
    clReleaseKernel(kernel);

if (program != 0)
    clReleaseProgram(program);

if (context != 0)
    clReleaseContext(context);

}

///
// main() for HelloWorld example
//
int main(int argc, char** argv)
{
clock_t begin,end;
double time_spent;
begin = clock();

cl_context context = 0;
cl_command_queue commandQueue = 0;
cl_program program = 0;
cl_device_id device = 0;
cl_kernel kernel = 0;
cl_mem memObjects[3] = { 0, 0, 0 };
cl_int errNum;

// Create an OpenCL context on first available platform
context = CreateContext();
if (context == NULL)
{
    std::cerr &lt;&lt; "Failed to create OpenCL context." &lt;&lt; std::endl;
    return 1;
}

// Create a command-queue on the first device available
// on the created context
commandQueue = CreateCommandQueue(context, &device);
if (commandQueue == NULL)
{
    Cleanup(context, commandQueue, program, kernel, memObjects);
    return 1;
}

// Create OpenCL program from HelloWorld.cl kernel source
program = CreateProgram(context, device, "HelloWorld.cl");
if (program == NULL)
{
    Cleanup(context, commandQueue, program, kernel, memObjects);
    return 1;
}

// Create OpenCL kernel
kernel = clCreateKernel(program, "hello_kernel", NULL);
if (kernel == NULL)
{
    std::cerr &lt;&lt; "Failed to create kernel" &lt;&lt; std::endl;
    Cleanup(context, commandQueue, program, kernel, memObjects);
    return 1;
}

// Create memory objects that will be used as arguments to
// kernel.  First create host memory arrays that will be
// used to store the arguments to the kernel
float result[ARRAY_SIZE];
float a[ARRAY_SIZE];
float b[ARRAY_SIZE];
for (int i = 0; i &lt; ARRAY_SIZE; i++)
{
    a[i] = (float)i;
    b[i] = (float)(i * 2);
}

if (!CreateMemObjects(context, memObjects, a, b))
{
    Cleanup(context, commandQueue, program, kernel, memObjects);
    return 1;
}

// Set the kernel arguments (result, a, b)
errNum = clSetKernelArg(kernel, 0, sizeof(cl_mem), &memObjects[0]);
errNum |= clSetKernelArg(kernel, 1, sizeof(cl_mem), &memObjects[1]);
errNum |= clSetKernelArg(kernel, 2, sizeof(cl_mem), &memObjects[2]);
if (errNum != CL_SUCCESS)
{
    std::cerr &lt;&lt; "Error setting kernel arguments." &lt;&lt; std::endl;
    Cleanup(context, commandQueue, program, kernel, memObjects);
    return 1;
}

size_t globalWorkSize[1] = { ARRAY_SIZE };
size_t localWorkSize[1] = { 1 };

// Queue the kernel up for execution across the array
errNum = clEnqueueNDRangeKernel(commandQueue, kernel, 1, NULL,
                                globalWorkSize, localWorkSize,
                                0, NULL, NULL);
if (errNum != CL_SUCCESS)
{
    std::cerr &lt;&lt; "Error queuing kernel for execution." &lt;&lt; std::endl;
    Cleanup(context, commandQueue, program, kernel, memObjects);
    return 1;
}

// Read the output buffer back to the Host
errNum = clEnqueueReadBuffer(commandQueue, memObjects[2], CL_TRUE,
                             0, ARRAY_SIZE * sizeof(float), result,
                             0, NULL, NULL);
if (errNum != CL_SUCCESS)
{
    std::cerr &lt;&lt; "Error reading result buffer." &lt;&lt; std::endl;
    Cleanup(context, commandQueue, program, kernel, memObjects);
    return 1;
}

// Output the result buffer
for (int i = 0; i &lt; ARRAY_SIZE; i++)
{
    std::cout &lt;&lt; result[i] &lt;&lt; " ";
}
std::cout &lt;&lt; std::endl;
std::cout &lt;&lt; "Executed program succesfully." &lt;&lt; std::endl;
Cleanup(context, commandQueue, program, kernel, memObjects);

end = clock();
time_spent = (double)(end - begin) / CLOCKS_PER_SEC;
std::cout&lt;&lt; std::endl&lt;&lt; std::endl&lt;&lt;"Running in GPU" &lt;&lt; std::endl&lt;&lt;std::endl;
std::cout &lt;&lt; "Total Execution Time :: " &lt;&lt; time_spent &lt;&lt; " Seconds" &lt;&lt;std::endl;
//printf("Total Execution Time :%Lf", time_spent);

return 0;

}