cocos2d-x undefined reference error need help...!!

Looking for some help,Iam new to cocos2dx and having error.iam using Eclipse IDE

inside HelloWorld.cpp iam doing this:

_backgroundNode = CCParallaxNodeExtras::node();
and it gives me undefined reference error which is as follows

undefined reference to 'CCParallaxNodeExtras::node()'

My CCParallaxNodeExtras.h header file code is as follows it inherits CCParallaxNode
@
`using namespace cocos2d;
#include “cocos2d.h”

class CCParallaxNodeExtras : public cocos2d::CCParallaxNode {

public :

// Need to provide a constructor
CCParallaxNodeExtras();

// just to avoid ugly later cast and also for safety
static CCParallaxNodeExtras* node();

// Facility method (it’s expected to have it soon in COCOS2DX)
void incrementOffset(CCPoint offset, CCNode* node);

};

#endif@ here is the CCParallaxNodeExtras.cpp @#include “CCParallaxNodeExtras.h”
using namespace cocos2d;

// Hack to access CCPointObject (which is not a public class)
class CCPointObject : cocos2d::CCObject {
CC_SYNTHESIZE(cocos2d::CCPoint, m_tRatio, Ratio)
CC_SYNTHESIZE(cocos2d::CCPoint, m_tOffset, Offset)
CC_SYNTHESIZE(cocos2d::CCNode *, m_pChild, Child) // weak ref
};

// Need to provide a constructor
CCParallaxNodeExtras::CCParallaxNodeExtras() {
cocos2d::CCParallaxNode(); // call parent constructor
}

CCParallaxNodeExtras* CCParallaxNodeExtras::node() {
return new CCParallaxNodeExtras::CCParallaxNode();
}

void CCParallaxNodeExtras::incrementOffset(cocos2d::CCPoint offset,CCNode *node){
for( unsigned int i = 0; i < m_pParallaxArray->num; i++) {
CCPointObject *point = (CCPointObject *)m_pParallaxArray->arr[i];
CCNode *curNode = point->getChild();
if( curNode->isEqual(node) ) {
point->setOffset( ccpAdd(point->getOffset(), offset) );
break;
}
}
}`
@
Please Reply, I Know there is a lot of code above but i want to know if iam doing anything wrong.Any Help or suggesstion will be appreciated.Thanks!

Regards,
Muhammad Tahir Ashraf