Magento 1 send ajax request.

magento1_ajax.js

new Ajax.Request("<?= Mage::helper('adminhtml')->getUrl('adminhtml/password/securitycheck') ?>", {
                method:     'POST',
                parameters: {'password': password},
                requestHeaders: {Accept: 'application/json'},
                onSuccess: function(response){
                    // Parse text as JSON
                    response = JSON.parse(response.responseText);
                    // Redirect
                    window.location.href = deleteURL;
                }
              });