WaitKey fails to compile

Hello, I’m starting with jetson nano, I trying a small openCV example. This:

#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc.hpp>

int main()
{

char k;

cv::Mat img (512,512,CV_8UC3, cv::Scalar(0));

cv::putText(img,
“Hello, OpenCV on Jetson!”,
cv::Point(10,img.rows/2),
cv::FONT_HERSHEY_DUPLEX,
1.0,
CV_RGB(118,185,0),
2);

cv::imshow(“Hello!”,img);

k = cv::waitkey(0);
}
But I got the following error:

/home/jorge/Documentos/testopencv/hello.cpp: In function ‘int main()’:
/home/jorge/Documentos/testopencv/hello.cpp:21:11: error: ‘waitkey’ is not a member of ‘cv’
k = cv::waitkey(0);
^~~~~~~
/home/jorge/Documentos/testopencv/hello.cpp:21:11: note: suggested alternative: ‘waitKey’
k = cv::waitkey(0);
^~~~~~~

But I don’t see the problem. Any idea?. I using a fresh install on my jatson nano.
Thanks in advance.
/Jorge

Finally I found the problem. It was a wrong uppercase.
The instruction have to be with uppercase K.
cv::waitKey(0);

/Jorge