Here is one of the best online available tool for UI Mockups Click on the containers tab, and drag a new dialog/window onto the page. Click the dialog/window and then look at the little pop-up on the right. You can trivially add a scrollbar and indicate where the thumb should be. You can turn on/off the icons in the top right corner. Adjust the status bar region. Its very user friendly and very easy to use .. we folks can have hand on this… We need to download this for use… here is the print screen of application Interesting point is even Microsoft Expression team is coming up with SketchFlow in its coming BLEND 3. This will be great[…]

One of the very important role of any UI expert to avoid or deal with mistaken or unsucceessful situations.Some of these situations may be detected or predicted during interaction are the list of.. Passive Prevention: errors that are prevented by documentation or online instructions. Active prevention: Errors that will be actively prevented by the system Supported prevention: Situations which the system detects as being potential errors, but whose decision is left to the user. Error Capture: Errors that are identified by the system and that should be notified to users Supported error handling: errors that should be corrected by the user, with system support. Rajesh R. Nair