add: if (! digilib) return; 
context:     function onImgLoad() {		// make sure the image is loaded so we know its size		/* this test seems to have problems sometimes :-(	    if (defined(digilib.scalerImg.complete) && !digilib.scalerImg.complete) {			alert("ERROR: the image seems not to be complete in onImgLoad!?");		} */	    digilib.trafo = digilib.parseTrafo(digilib.scalerImg);	    // display marks	    digilib.renderMarks();		digilib.showBirdDiv(isBirdDivVisible);		digilib.showArrows();		// show arrow overlays for zoom navigation		//digilib.moveCenter(true);	// click to move point to center		// new Slider("sizes", 1, 5, 2);	    focus();	}
meta: 7747	/local1/tlutelli/issta_data/temp/all_js/javascript/2007_temp/2007/7747/70c2b5c9d0fe01d0c6399a5841b87e9e85ffb188/dllib.js/buggy/client/digitallibrary/greyskin/dllib.js