Urgent Please solve the problem

[toseefasim]

#include<iostream.h>
#include<stdlib.h>
#include<conio.h>
#include<string.h>
class Virtual_Ballot_Paper
{
private:
int NoOfsigns;
char *NameOfVotingCategory;
public:
Virtual_Ballot_Paper()
{
NoOfsigns = 0;
NameOfVotingCategory = NULL;
}

void DisplaySign();
~Virtual_Ballot_Paper(){}


};
class Candidate : public Virtual_Ballot_Paper
{
private:
char* Name;
char* Address;
char* CandidateType;
int NoVotes;
public:
Candidate()
{
Name = Address = CandidateType = NULL;
NoVotes = 0;
}
Candidate(char *n ,char *a ,char *c ,int x)
{
Name = n;
Address = a;
CandidateType = c;
NoVotes = x;

}
~Candidate(){}

};

class Sign : public Candidate
{
private:
char *Name;
public:
void Select();
~Sign()
{
}
};

class Constituency : public Candidate
{
private:
int NoOfCandidates;
int NoOfVoters;
int ConstituencyNo;
public:
Constituency()
{
NoOfCandidates = 0;
NoOfVoters = 0;
ConstituencyNo = 0;
}
Constituency(int n ,int x ,int c)
{
NoOfCandidates = n;
NoOfVoters = x;
ConstituencyNo = c;
}
int GetConstituencyNo();
~Constituency(){}
};
class Result : public Virtual_Ballot_Paper
{
public:
int CountVotes();
int AnnounceResult();
~Result(){}
};

---------------------------------
Please inform me what are the errors in the program as error received is as under:

Compiler: Default compiler
Compiler: Default compiler
Executing g++.exe...
g++.exe "C:\Users\Asim\Desktop\mc110203911cs304.cpp" -o "C:\Users\Asim\Desktop\mc110203911cs304.exe" -I"C:\Dev-Cpp\include\c++\3.3.1" -I"C:\Dev-Cpp\include\c++\3.3.1\mingw32" -I"C:\Dev-Cpp\include\c++\3.3.1\backward" -I"C:\Dev-Cpp\lib\gcc-lib\mingw32\3.3.1\include" -I"C:\Dev-Cpp\include" -L"C:\Dev-Cpp\lib"
In file included from C:/Dev-Cpp/include/c++/3.3.1/backward/iostream.h:31,
from C:/Users/Asim/Desktop/mc110203911cs304.cpp:1:
C:/Dev-Cpp/include/c++/3.3.1/backward/backward_warning.h:32:2: warning: #warning This file includes at least one deprecated or antiquated header. Please consider using one of the 32 headers found in section 17.4.1.2 of the C++ standard. Examples include substituting the <X> header for the <X.h> header for C++ includes, or <sstream> instead of the deprecated header <strstream.h>. To disable this warning use -Wno-deprecated.

C:\Dev-Cpp\lib/libmingw32.a(main.o)(.text+0x106):main.c: undefined reference to `WinMain@16'

Execution terminated
----------------------------------
1 C:\Dev-Cpp\include\c++\3.3.1\backward\iostream.h:31, from C:\Users\Asim\Desktop\mc110203911cs304.cpp In file included from C:/Dev-Cpp/include/c++/3.3.1/backward/iostream.h:31, from C:/Users/Asim/Desktop/mc110203911cs304.cpp

1 C:\Users\Asim\Desktop\mc110203911cs304.cpp from C:/Users/Asim/Desktop/mc110203911cs304.cpp

2 C:\Dev-Cpp\include\c++\3.3.1\backward\backward_warning.h:32 #warning This file includes at least one deprecated or antiquated header. Please consider using one of the 32 headers found in section 17.4.1.2 of the C++ standard. Examples include substituting the <X> header for the <X.h> header for C++ includes, or <sstream> instead of the deprecated header <strstream.h>. To disable this warning use -Wno-deprecated.

[Linker error] undefined reference to `WinMain@16'

[MiiNiPaa]

a) You are using <iostream.h> <stdlib.h> and <string.h> headers which are deprecated and shouldn't be used. (my compiler doesn't have iostream.h already) Use <iostream>, <cstdlib> and <cstring> instead.
b) You do not have main() function anywhere. Either you just doesn't have it, or file containing it doen't included in to-compile list.