各位大侠，我想在wincc v7.0 OnlineTrendContrl控件上动态添加曲线变量记录

以下是C脚本：

//趋势控件取消激活  

SetPropBOOL(lpszPictureName,"RealtimeChart","Activate",FALSE);      

 // 设置趋势控件属性  

SetPropBOOL(lpszPictureName,"RealtimeChart","Visible",TRUE);            //趋势控件可见

  SetPropWord(lpszPictureName,"RealtimeChart","NumItems",2);     //趋势控件包含曲线数目

 //设置第一条曲线属性   

SetPropWord(lpszPictureName,"RealtimeChart","Index",0);                //第一条曲线为0

/SetPropBOOL(lpszPictureName,"RealtimeChart","ItemVisible",TRUE);           //第一条曲线可见 

//SetPropChar(lpszPictureName,"RealtimeChart","Name","1#主机冷冻进水温度");              //第一条曲线名称 

//SetPropChar(lpszPictureName,"RealtimeChart","Label","NewTagT1");              //数值轴标签名  

SetPropWord(lpszPictureName,"RealtimeChart","Color",255); //曲线颜色

SetPropChar(lpszPictureName,"RealtimeChart","TagName","NewTagT1"); //在线变量  

SetPropWord(lpszPictureName,"RealtimeChart","BeginValue",0);       //量程下限，可自定义 

SetPropWord(lpszPictureName,"RealtimeChart","EndValue",100);      //量程上限，可自定义  

//第二条曲线

SetPropWord(lpszPictureName,"RealtimeChart","Index",1);                

SetPropWord(lpszPictureName,"RealtimeChart","Color",0xff00); 

SetPropChar(lpszPictureName,"RealtimeChart","TagName","NewTagT2"); //在线变量

//趋势控件激活  

SetPropBOOL(lpszPictureName,"RealtimeChart","Activate",TRUE); 

为什么不行啊？是哪里出错了