I have aproblem in visual studio 2008

sorry for being late :)
im using vc++ ,,for my graduation project
when iam using this code
#include"stdafx.h"
#include"omp.h"
#include"iostream"
using namespace std;
int main()
{
int **a,**b,**c; // variables to store allocated memory
int a_r,a_c,b_r,b_c, nthreads, tid, chunk =10; //variables to input matrix
//size and variables to be used by OpenMP functions
double dif,st,et; //variable to calculate the time difference between the parallelization
int i,j,n,m; // variables to be used in for loops to
//generate matrices
cout<<"\nenter rows and columns for the matrix:";
cin>>a_r>>a_c;
cout<<"\nenter rows and columns for the mask :";
cin>>b_r>>b_c;
/* allocate memory for matrix one */
a=(int **) malloc(10*a_r);
for( i=0;i<a_c; i++)
{
a[i]="(int" *)="" malloc(10*a_c);
}
="" *="" allocate="" memory="" for="" matrix="" two=""
b="(int" **)="" malloc(10*b_r);
for(="" i="0;i<b_c;" i++)=""
{
b[i]="(int" malloc(10*b_c);
}
="" sum=""
c="(int" malloc(10*a_r);
for(="" a_c;="" i++)
{
c[i]="(int" malloc(10*a_c);
}
cout&lt;&lt;"enter="" the="" index="" of="" center="" mask="" :"&lt;&lt;endl;
cin="">>n;
cin>>m;

#pragma omp parallel num_threads(1) shared(a,b,c,nthreads,chunk) private(tid,i,j)
{
tid = omp_get_thread_num();
if (tid == 0)
{
nthreads = omp_get_num_threads();
cout<<"Starting matrix multiple example with "<<nthreads<<"threads";
}
st =omp_get_wtime();
//initializing first matrix
#pragma omp for schedule (static, chunk)
for(i=0;i<a_r; i++)
{
for(j="0;j<a_c;" j++)
{
a[i][j]="i+j;
}
}
//" initializing="" second="" matrix
#pragma="" omp="" for="" schedule="" (static,="" chunk)
for(i="0;i<b_r;" j++)
{
b[i][j]="i*j;
}
}
/*initialize" product="" matrix="" *=""
#pragma="" b_c;="" j++)
{
c[i][j]="0;
}
}



#pragma" i++)
{
="" printf("thread="%d" did="" row="%d\n",tid,i);
for(j=0;j<a_c;">=0&&j-1>=0)
c[i][j]=c[i][j]+a[i-1][j-1]*b[n-1][m-1];

if(i+1<a_r&&j+1<a_c)
c[i][j]=c[i][j]+a[i+1][j+1]*b[n+1][m+1];

if(i-1>=0)
c[i][j]=c[i][j]+a[i-1][j]*b[n-1][m];

if(i+1<a_r)
c[i][j]=c[i][j]+a[i+1][j]*b[n+1][m];

if(i+1<a_r&&j-1>=0)
c[i][j]=c[i][j]+a[i+1][j-1]*b[n+1][m-1];

if(i-1>=0&&j+1<a_c)
c[i][j]=c[i][j]+a[i-1][j+1]*b[n-1][m+1];

if(j-1>=0)
c[i][j]=c[i][j]+a[i][j-1]*b[n][m-1];

if(j+1<a_c)
c[i][j]=c[i][j]+a[i][j+1]*b[n][m+1];

}
}
} *****end="" of="" parallel="" region*****=""
cout&lt;&lt;"******************************************************\n";
cout&lt;&lt;"done.\n";
="" et="omp_get_wtime();

dif=et-st;
cout<<"Parallelization" took="" "&lt;&lt;dif&lt;&lt;"sec.="" time.\n";



="" *free="" memory*=""
for(i="0;i<a_r;" i++)
{
free(a[i]);
}
free(a);
for(i="0;i<b_c;" i++)
{
free(b[i]);
}
free(b);
for(i="0;i<a_c;" i++)
{
free(c[i]);
}
free(c);
int="" kkk;cin="">>kkk;



return 0;
}
i think i have aproblem in visual studio installation??what do you think

error LNK2019: unresolved external symbol _main referenced in function ___tmainCRTStartup
fatal error LNK1120: 1 unresolved externals
how can solve them ,,plz help me!!