Textbox with alphanumeric check in javascript

Question

I have a textbox, and it needs not allow the user to enter any special characters. He can enter:

1. A-Z
2. a-z
3. 0-9
4. Space.

O

Answer 1

Now that we have HTML5, you don't even need to use JavaScript. You can use the pattern attribute.

The pattern attribute should contain a regular expression defining the format. And title should contain a human-readable description of the format.

Then on validation, depending on the browser, the browser will outline the field in red and/or display a message stating your description of the format.

This tutorial goes into more detail: HTML5 Input Validation Tutorial.