The simplest change you can make to your forms is to mark a text input field as 'required': This informs the (HTML5-aware) web browser that the field is to be considered mandatory.
Different browsers may mark the input box in some way (Firefox 4 Beta adds a red box-shadow by default), display a warning (Opera) or even prevent the form from being submitted if this field has no value.
Before you ask, and someone always does, these examples will currently work in the following browsers: Safari 5, Chrome 6, Opera 9, Firefox 4 Beta and the i Phone/i Pad.
Also each browser has a slightly different default behaviour.
Obviously neither example is very limiting, but it will prevent people from entering completely wrong values, such as phone number, strings with multiple '@'s or spaces.
Here is how the two inputs are displayed in Safari: and in Opera: They are currently not supported in Firefox 4 Beta. For example it is perfectly valid for an email address to go to the MX handler for a top level domain.
If you want to restrict the input of a text field to numbers without having the up/down arrows associated with the input box, you can always just set the input type to of "\d " (one or more numbers). So something along the line of important.person@ca would be perfectly valid! Anyone out there know how to adjust the url validation so that it will accept inputs in the following format: no need to force a user to input or https:// You can find a comparison of some interesting regexes for validating URLs here.
Of course, if you're having trouble with curly braces in C#, this question would be the least of your worries...@Void King You are correct about the curly braces but if you only have 1 statement in that block you don't have to use them. Personally I prefer Try Parse Exact with a specific format, but I guess there are times when Try Parse is better.
This applies in some other languages as well but I can see how this can be misleading to newer coders.@D. Example use based on your original code: Welcome to Stack Overflow!
As soon as a single character has been entered this changes to a green marker to indicate that the input is 'valid'.