Function for Viewing MRI Slices

This simple function allows the user to view the saggital, coronal and horizontal slices of a certain .nii format MRI scan. All you need to do is enter the x, y and z coordinates of a certain point to be able to view the slices that pass through that certain point. Colormap is set automatically to gray, but can be changed if desired.
The function uses the load_nii function from Jimmy Shen's "Tools for NIfTI and ANALYZE image" toolbox, and will not work without it.