问一个菜菜的问题，CVI中用的是标准C吗？C-的语法规则不能用？

我写了一段程序，
BYTE*  pRGBData;    /*24位RGB数据指针*/
DWORD RGBDataSize = 1280*1024*3;
pRGBData =(BYTE*)malloc(RGBDataSize*sizeof(BYTE));
memset(pRGBData,0,RGBDataSize);    
编译器显示很多错误：
           Redeclaration of 'pRGBData' previously declared at ShadowMask.c:14.
  20, 50   Invalid initialization type; found 'pointer to BYTE' expected 'int'.
  21, 31   Redeclaration of 'memset' previously declared at string.h:36.
  23, 49   Invalid initialization type; found 'pointer to BYTE' expected 'int'.
  24, 31   Extraneous formal parameter specification.
  24, 31   Redeclaration of 'memset' previously declared at ShadowMask.c:21.
请高手指点一下，谢谢