Checking in javascript (with jQuery) that the entered price is equal or greater than the minimum listing price.

Minimum listing price

// Always check that jQuery is available before executing the script
$(document).ready(function() {

    // Execute only if the listing form exists in the page
    if($('#listingForm').length > 0) {
    
        var checkMinimumListingPrice = function() {  
            // Check if the price is equal or greater than 1
            if($('#ListingPrice').val() < 1) {
               alert('Price should be equal or greater than 1');
               return false;
            }
            return true;
        };
    
        // Check when form is submitted
        $(document).on('submit', '#listingForm',  function() {  
           if(!checkMinimumListingPrice()) {
               return false;
           }
        });
        
        // Check when the price field is filled
        $('#listingForm').on('focusout', '#ListingPrice', function() {  
           if(!checkMinimumListingPrice()) {
               return false;
           }
        });
    }

});