error background image to a windows form

[C# Programming]

i am on a windows project and i applied backgroundimage to all the forms earlier. And now when i want to apply another new background image to a form then , i can see the new image as background image to a form in visual studio but at the runtime no image is displayed, and the form is displayed with background color but not with the image. After that through code also i tried using imagelist . Then indexoutofrange exception is coming.
Please suggest me the required answer. Urgent.