In Magento 1.9,
I would like the product price to update ONLY when customer input more than 5 characters (or multiple the change-price for every 5 character added, if not too complex).
* The "price change Value" is set via the backend custom option, as below
I want to add if-else to decide the onchange event, but fail to get current user input length.
<input type="text" onchange="opConfig.reloadPrice()" id=...>
Can anyone help? Thanks in advance!