// The native width and height of the image.
// Gets the image native height and width.
// Gets the image current height and width.
// Gets .maginfy offset coordinates.
// Gets coordinates within .maginfy.
// Checks the mouse within .maginfy or not.
so deduct the half of .large width and height.
var e = window.event || e; // old IE support.
// Gets the image scaling height and width.
// Update backgroud image size.
// Combines object defaults and options.
e = window.event || e; // old IE support.
// The image can't smaller than the original.