修改OpenLayer的图片路径

OpenLayers.ImgPath = "images/openlayers/";

your image path in your web project, and in the folder you must provide the same name images as in the openalyers/image floder. such as  below:　

blank.gif
close.gif
close_new.gif
cloud-popup-relative.png
east-mini.png
layer-switcher-maximize.png
layer-switcher-minimize.png
north-mini.png
slider.png
south-mini.png
west-mini.png
zoom-minus-mini.png
zoom-plus-mini.png
zoom-world-mini.png
zoombar.png