display image from a Sharepoint library on mouseover on the image displayed in webpart

I have two Picture Libraries. One has pictures and the other contains the thumbnails created programmatically by me. I am displaying the thumbnails into a custom webpart. I need to display the original pictures on mouseover on the thumbnails displayed 开发者_运维问答in webpart and the originals displayed should dissappear on mouse out.

Please Help. I am a new sharepoint developer

You don't need to create separate PictureLibrary for thumbnails, SharePoint will do it automatically for you. So when you upload images to Picture Library 'ABC', SharePoint will create two hidden folders inside ABC folder: _t for thumbnails (path: ABC/_t/) and _w for previews (path: ABC/_w/).