extern CGFloat __ccContentScaleFactor; redefination error

I have developed a game in cocs2d than don't allow me to compile on 64 bit architecture and gives error as below

1.Error At Line

extern CGFloat __ccContentScaleFactor;

2.Error

Redefination of '__ccContentScaleFactor' with a different type 'CGFloat'('aka double') vs ('float')

same error after adding CGFloat __ccContentScaleFactor = 1;