error LNK2001 unresolved symbol

[g_arunar]

#include<iostream>
using namespace std;
class OprOvld{
public:
	int var1,var2;
	OprOvld();
	OprOvld(int v1, int v2){
		var1=v1;
		var2=v2;
	}
	void display(){
		cout<<var1<<endl;
		cout<<var2<<endl;
	}
	OprOvld operator+ (OprOvld l);
};

OprOvld OprOvld::operator+ (OprOvld l){
	OprOvld temp;
	temp.var1=l.var1+var1;
	temp.var2=l.var2+var2;
    return temp;
}

int main(int argc, char* argv[]){
	OprOvld ov1(1,5), ov2(3,6);
	ov1.display();
	ov2.display();
	ov1=ov1+ov2;
	ov1.display();
	return 0;
}

for the above program I get Linker Error.... The error is pasted below

Linking...
Op_Ovld.obj : error LNK2001: unresolved external symbol "public: __thiscall OprOvld::OprOvld(void)" (??0OprOvld@@QAE@XZ)
Debug/Op_Ovld.exe : fatal error LNK1120: 1 unresolved externals
Error executing link.exe.




Can some one please help me with this Issue.