func convertHalfFromString(fullStr: String) -> String{
    let srcStr = fullStr.stringByReplacingOccurrencesOfString("。",withString: ".")
    let cfstr = NSMutableString(string: String(srcStr)) as CFMutableString
    var range = CFRangeMake(0,CFStringGetLength(cfstr))
    CFStringTransform(cfstr,&range,kcfStringTransformFullwidthHalfwidth,Bool(0))
    return cfstr as String
}