Add custom validation to property

gistfile1.txt

add_action( 'propertyhive_property_address_fields', 'add_property_address_validation' );
function add_property_address_validation()
{
?>
<script>

    jQuery('.wrap form').submit(function()
    {
        if (jQuery(this).find('input[name=\'_address_three\']').val() == '')
        {
            alert('Please enter the property town/city');
            return false;
        }

        return true; // passed validation
    });

</script>
<?php
}