load ajax using admin-ajax.php

The codex says here that The wp_ajax_ hook follows the format “wp_ajax_$youraction”, where $youraction is your AJAX request’s ‘action’ property.

I suppose in your js file you should go for:

data: {
            action: 'lateral_fluid', // the $action to run
      }

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)