Is it possible to create an input field that sets the default input character set to numbers on a mobile phone (so the NUMERICAL KEYBOARD POPS UP)?
For example to make it easier type in a telephone number into a HTML form.
To make inputing numbers easier, use <input type="number">
. To make entering phone numbers easier, use <input type="tel">
. Not all phone will support them, but the iPhone at least will give you a numeric keypad by default instead of the normal keyboard. See the spec and Dive Into HTML5 for more information.