trying to inherit

hi, im trying to inherit from class but the same error is appearing

Code:

1>c:\users\kthdu_000\documents\visual studio 2010\projects\rectangle\rectangle1\crectangle.h(1): error C2011: 'Crectangle' : 'class' type redefinition

the following is my classes

crectangle.h

Code:

class Crectangle{


protected:
	int m_x;
	int m_y;
public:
    void setvalue(int x,int y);
	int getarea(void);
};

cperrect.h

Code:

#include "Crectangle.h"


class Cperrect : public Crectangle{




public  :


	int perimter();




};

Cperrect.cpp

Code:

#include "Cperrect.h"
#include <iostream>


int Cperrect::perimter(void){
	int ans;


	ans =(m_x + m_y)*2;




	return ans;
}

crectangle1.cpp

Code:

#include<iostream>
#include"Crectangle.h"
 void Crectangle::setvalue(int x,int y){
	 
	 m_x = x;
	 m_y = y;
}
 int Crectangle::getarea(void){


	 return m_x*m_y;
 }

Main.cpp

Code:

#include <iostream>
#include "Crectangle.h"
#include "Cperrect.h"
void main(){
	int x1=0,y1=0;
	Crectangle rect;
	Cperrect prect;
	std::cout<<"please enter 2 number";
	std::cin>> x1>>y1;
	rect.setvalue(x1,y1);
	prect.setvalue(x1,y1);
	std::cout<< "area "<<rect.getarea();
	std::cout<< "perimeter "<<prect.perimter();
}

Your header files are missing include guards.

Also: SourceForge.net: Void main - cpwiki
And using "void" in the parameter list when it takes no parameters in C++ is an archaic convention. You don't need it.