we need to set validation in textfield : "zip code" under checkout process in magento site.
i need to restrict this textfield for maximum 6 digits.
i am using following code for this :
<input type="text" title="<?php echo $this->__('Zip/Postal Code') ?>"
name="billing[postcode]" id="billing:postcode"
value="<?php echo $this->escapeHtml($this->getAddress()->getPostcode()) ?>"
class="input-text validate-zip-international
<?php echo $this->helper('customer/address')->getAttributeValidationClass('postcode') ?>" placeholder="Postal code"/>
please help me to give validation for Restricting only for 6 digits