xmlDocPtr doc; 
    xmlNodePtr root; 
    // load an exist xml file. 
    doc = xmlParseFile("test.xml"); 
    if (doc == NULL )  
    {  
        fprintf(stderr,"Document not parsed successfully. \n");  
        return 0;  
    }  
    // get root 
    root = xmlDocGetRootElement(doc); 
    if (root == NULL)  
    {  
        fprintf(stderr,"empty document\n");  
        xmlFreeDoc(doc); 
        return 0; 
    } 

    void CreateNewXMLDemo() 
    { 
        // create xml document 
        xmlDocPtr doc = xmlNewDoc(BAD_CAST"1.0"); 
        xmlNodePtr root = xmlNewNode(NULL,BAD_CAST"root"); 

        //set root 
        xmlDocSetRootElement(doc,root); 

        //add node 
        xmlNewTextChild(root, NULL, BAD_CAST "newNode1", BAD_CAST "newNode1 content"); 
        xmlNewTextChild(root, NULL, BAD_CAST "newNode2", BAD_CAST "newNode2 content"); 
        xmlNewTextChild(root, NULL, BAD_CAST "newNode3", BAD_CAST "newNode3 content"); 

        //create node and add content 

        xmlNodePtr node = xmlNewNode(NULL,BAD_CAST"node2"); 
        xmlNodePtr content = xmlNewText(BAD_CAST"NODE CONTENT"); 
        xmlAddChild(root,node); 
        xmlAddChild(node,content); 

        // add attribute 
        xmlNewProp(node,BAD_CAST"attribute",BAD_CAST "yes"); 

        //create son and grandson 

        node = xmlNewNode(NULL, BAD_CAST "son"); 
        xmlAddChild(root,node); 
        xmlNewTextChild(node, NULL, BAD_CAST "grandson", BAD_CAST "grandson content"); 

        xmlNodePtr grandson = xmlNewNode(NULL, BAD_CAST "grandson2"); 
        xmlAddChild(node,grandson); 
        xmlAddChild(grandson, xmlNewText(BAD_CAST "This is a grandson2 node")); 

        //save xml 

        int nRel = xmlSaveFile("test3.xml",doc); 

        if (nRel != -1) 
        { 
            cout<<"create a xml:"<<nRel<<"bytes"<<endl; 
        } 

        //release 

        xmlFreeDoc(doc); 
    } 

    xmlNodePtr head = root->children->next; 
    while(head != NULL) 
    { 
        if(head->type == XML_ELEMENT_NODE) 
        { 
            cout<<"Name:"<<head->name<<endl; 
            cout<<"Content:"<<xmlNodeGetContent(head->children)<<endl; 
            // update test05 
            if ((!xmlStrcmp(head->name, (const xmlChar *)"test05"))) 
            { 
                xmlNodeSetContent(head->children,(const xmlChar *)"orz05"); 
            } 

            // remove node 
            if (!xmlStrcmp(head->name, BAD_CAST "test07")) 
            { 
                xmlNodePtr tempNode; 
                tempNode = head->next; 
                xmlUnlinkNode(head); 
                xmlFreeNode(head); 
                head = tempNode; 
                continue; 
            } 
        } 
        head = head->next; 
    }