I don't think there is any way of identifying whether a file is an image file or not unless we know the datastructures used to save each type of the file. Images are just binary files. Graphic applications which support multiple image types know this. But such a component may not be available in the public domain. You may check GIMP project. But it will be a touch job.

Thanks Heath for your reply. I have gone through the CAS article you had suggested. It is very informative. However, I have to still go through it a couple of times before I can digest. The impression I got is that CAS is for stopping unauthorized user to execute the code. However, the problem I have been facing is at design time. For the problem to be easily understood, I have created a small project. I am attaching a zip file of the project. This project successfully compiles. You can execute the same. But to observe the current problem, do the following: Open the solution in VS 2003. This contains a Test project. This contains three forms - FrmMain, CSIBaseForm, FrmUser. FrmUser inhertis from CSIBaseForm which in turn inherits from System.Windows.Forms.Form. I double click on the FrmUser form to view it in design mode. It does not show. Could you tell me what the problem is and what I should do to overcome it? There does not seem to be a way of attaching the zip file here. I shall send it directly to your e-mail address. Thanks.

Thanks Heath, When I wrote "It is not even running" I meant I did not even execute. Yes, it is running. The problem I am referring to occurs at design time - not at run time. Since I am not executing the code, I thought the IO error should not have occured. However, VS IDE probably is trying to execute the MyBaseForm code so as to display the form in design mode. So, this morning I changed the security to FullTrust - for the module that contains MyBaseForm. However, when tried to view MyScreenForm in design mode, it still did not work. Request help. Thanks once again. Snnn

I would like a place holder class btween my Screen Form and Windows Form. So, I create MyBaseForm class that inherits from System.Windows.Forms.Form. Then I create MYScreenForm class that inherits from MyBaseForm. However, at design time, I am not able to see the MyScreenForm. It gives the following error: Request for the permission to type System.Security.Permissions.FileIOPermission, mscorlib, Version=1.0.5000.0, Culture=neutral, PublicKeytoken=.... failed. Thus, I am not able todesign my screen visually. Note that I can place any controls programmatically and the code compiles and runs. Appreciate any explanations / help

snnn wrote: How can I get a dataset of selected rows in a DataGrid? It should get me the correct selected rows even if the grid is sorted on any one of the columns. I am still looking forward for an answer. Would anyonr please help?

How can I get a dataset of selected rows in a DataGrid? It should get me the correct selected rows even if the grid is sorted on any one of the columns.

Add a new project for your application solution. This project should be a Setup project. You can find it under New Project->Setup and Deployment Projects. Read the help on proceding further. This will give you a MSI file which can be installed on the client applications using Windows Installer.