PictureStretch stretch.htm - Stretch Image To Fit Form.
When this checkbox is checked background images will be stretched to fit the size of the form. Any change to this checkbox is only carried out when the form is resized or a new background picture is loaded.
N.B. If a grid uses a background.jpg file, where the word background
is replaced with the gridname prefix, i.e., if the input grid file is grid1803.txt
and the background image is grid1803.jpg, then the image is automatically
loaded by inGridX and the window is resized accordingly.