The fillMode attribute is used to control how an image reacts when the pixel dimensions of the source file are different than the height and width defined for the image object. There are two allowable values: "stretch" and "tile".
Stretch will simply scale the image source up or down to fit the given height and width of the image. Tile will leave the source at its original dimensions and will repeat it both horizontally and/or vertically as needed to meed the width and height defined.
Possible Values: Strings "stretch" or "tile"
If Omitted: The default value of "stretch" is used.
myObjectName.fillMode = "tile";
<fillMode = "tile" />