Ask Felgall

Sometimes the solution to a problem is extremely simple but not very obvious until you know what it is. One such simple solution relates to not losing the values already entered into a form when you want JavaScript to report validation errors.

Keeping Entered Values when Reporting an Error

p.s. why do so many people insist on misspelling lose (opposite of win) as loose (opposite of tight). Are people these days so reliant on spell checkers that they have forgotten how to spell even simple words?

Quite a few people visiting my web site send me questions about problems that they are having with their computer hardware because they can’t find an answer to their question on my site. The main reason why they can’t find the answer on my site is because the site is primarily about computer software and the extremely small number of pages dealing with hardware relate to specific problems that I have needed to resolve where I have had direct access to the computer in question either because the computer with the problem is mine or belongs to someone I know.

Hardware problems are almost impossible to properly diagnose without physically accessing the computer with the problem. The best that I can suggest for those with hardware problems is to follow through the basic steps themselves that I always start with when I need to resolve a hardware problem on a computer that I have in front of me.

Resolving Hardware Problems

There is nothing that you can do in the HTML, stylesheet, or JavaScript that will protect the images on your web site from being stolen. The best form of protection is to either place a watermark in the image itself or to embed the image into a PDF with associated text that indicates the copyright. Those methods will not prevent your image being stolen but will identify it as stolen when the thief tries to use it.

The next most effective way after that is an HTML solution which reduces the chance of casual theft of your images by placing them behind a second transparent image. This will mean that someone who steals images using their context menu will most likely save a copy of the transparent image instead of the one they intended to take and will possibly not notice until much later that they didn’t get the image they thought they had saved. This will not prevent them saving the image some other way but since you are not making it obvious that you have blocked their ability to save the image through their context menu they they may decide that it is not worth the effort of returning to your site to use some other method of saving the images.

Partial Protection of Images

One way in which JavaScript can make your forms more user friendly is where you have multiple dropdown lists where what is a valid selection in one list is dependent on what is selected in another list. Let’s take a look at how you can use JavaScript to link two dropdown lists together so that the entries displayed in the second list are dependent on what is selected in the first list.

Dynamic Dropdown Boxes

Note that theses are dropdown lists, not combo boxes, HTML does not have a tag for generating a combo box. A combo box is a combination of a dropdown list and a text input field since your visitor can either select an entry from the list or type their own value in a combo box.

Floppy disks are becoming less and less common. These days ju7st about all computers allow you to boot from the CD/DVD drive in order to be able to repair a system that has a damaged operating system that will not allow the hard drive to boot. If you still have an older computer that doesn’t allow you to boot directly from the cd to run the repair then you may still need floppy disks to start the boot process in which case this article on howe to make or obtain bootable floppies will be of interest.

Creating a Boot Disk

A discussion of what buffers and blocks are and how they can make a difference as to how efficiently a mainframe computer can read and write datasets.

Buffering and Blocks

Just about all browsers have a find on page option in the menu and so adding an equivalent option using JavaScript may not appear all that useful. It doesn’t work completely the same way as the built in ones do though since it uses a separate browser window rather than a dialog box and therefore doesn’t need to be closed in order to continue interacting with the page.

Find on this Page

The best ways of passing values from one page to another require server side scripting. That way they work for everyone and not just those with JavaScript enabled. There are a number of different situations where you need to pass values and this article looks at several situations and how to handle them with two different scripting languages.

Passing Values Between Pages