use <input type="number" id="loco.address_1" name="loco.address" min="-1" max="10239"> for loco.address use <label for="loco.address_1">DCC address: (-1 to disable)</label > [https://wiki.selfhtml.org/wiki/HTML/Tutorials/Formulare/input/number](https://wiki.selfhtml.org/wiki/HTML/Tutorials/Formulare/input/number)
use <input type="number" id="loco.address_1" name="loco.address" min="-1" max="10239"> for loco.address
use <label for="loco.address_1">DCC address: (-1 to disable)</label >
https://wiki.selfhtml.org/wiki/HTML/Tutorials/Formulare/input/number