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

This function will check the string given to it for those criteria:

function checkvalue(value) {
  return value.match( /[A-Za-z][A-Za-z0-9 ]*/ );
}

You can then use that in an onkeypress event, passing in the current value.