Load An Image Into Picturebox?

I am using VB.net and have a form that contains a picturebox and i have to load an image into it from another class. When i set image property of picturebox from other class it doesn't display the image. I think its something to do with display form intitialization but not sure. It works well if i put a button on the same form to display image but thats not what i want. I want to set the image from another class's function.I have a form with public class VBSample and this form contains a button "Take Picture" with an associated event controller.actionPerformed( "takepicture")Where controller is a controller for my attached camera. From here it goes to a controller handler of Public Class CameraController which actually takes the picture from camera. After taking the picture program control is transeferd to Public Class DownloadCommand which download the image from camera into a filestream and then stores it on hard disk...after copying the image into memory i want to display it in a picture box on my initial form which is Public Class VBSample but it says that picturebox cannot be referenced ....