Opencv reopens window while live webcaming + another little problem

[hakermania]

I have made a gui actually with 2 buttons. The first shows the output of the webcam and the second takes a picture from it and saves it!
That's the code for the first:

void campic::on_pushButton_2_clicked()
{
cvNamedWindow( "Webcam", CV_WINDOW_AUTOSIZE );

CvCapture* capture = cvCreateCameraCapture(0) ;
IplImage* frame;

while(1) {
frame = cvQueryFrame( capture );
if( !frame ) break;
cvShowImage( "Webcam", frame );
char c = cvWaitKey(33);
if( c == 27 ) break;

}
cvReleaseCapture( &capture );
cvDestroyWindow( "Webcam" );

}

This button is capturing video from the webcam. It has 2 main problems:
a)It does closes only with the [ESC] button, if I close the window from the X button it automatically reopens!
b)When I push again this button and there is already a live capture in progress then the program force-quits with the ERRORS:

HIGHGUI ERROR: V4L2: Pixel format of incoming image is unsupported by OpenCV
Unable to stop the stream.: Device or resource busy
Unable to stop the stream.: Bad file descriptor
HIGHGUI ERROR: V4L: Pixel format of incoming image is unsupported by OpenCV
The program has unexpectedly finished.

My logic says that the problem is that there is an already running webcaming and so these errors exist. A solution coulb be to check if there is an already webcaming progress and if it is then do nothing!

That's the code for the second button:

void campic::on_pushButton_clicked()
{ char home[150]="/home/";
  strcat(home,user); //user = USERNAME (getenv("USER"))
  char other[60]="/.config/program/webcam.jpg";
  strcat(home,other);

    CvCapture *pCapturedImage = cvCreateCameraCapture(0);

    // Get the frame
    IplImage *pSaveImg = cvQueryFrame(pCapturedImage);

    // Save the frame into a file
    cvSaveImage(home ,pSaveImg);
}

The problem with this is that it saves the image very well but if I push the button again it probably lets the webcam busy and the program force quits. I mean when I open the program and push this button it successfully takes a pic of me, but when I push again the button fro another picture it force quits! I am sure that it goes out of the void function because i can do other things on the program when having already push the button 1 time! So, these are the errors if I try to get another picture from the webcam:

HIGHGUI ERROR: V4L2: Pixel format of incoming image is unsupported by OpenCV
Unable to stop the stream.: Device or resource busy
Unable to stop the stream.: Bad file descriptor
HIGHGUI ERROR: V4L: Pixel format of incoming image is unsupported by OpenCV
OpenCV Error: Null pointer (NULL array pointer is passed) in cvGetMat, file /home/alex/OpenCV-2.1.0/src/cxcore/cxarray.cpp, line 2376
terminate called after throwing an instance of 'cv::Exception'
  what():  /home/alex/OpenCV-2.1.0/src/cxcore/cxarray.cpp:2376: error: (-27) NULL array pointer is passed in function cvGetMat
The program has unexpectedly finished.

There also seems to be a little problem with these two. For instance if I chose to take webcam output and while taking output then the program crashes as well... I think that at the beginning of any void function of the two existing must have a kind of check....