Form validation jquery problem

[eluser]V4Mp[/eluser]
I have a function wich das this

Code:

function check_exists_useraccount($account)
    {
        
        $query_str = "SELECT account from user_details where account = ?";
    
        $result = $this->db->query($query_str, $account);
        
        if ($result->num_rows() > 0)
        {
            //account exists
            return true;
            
        }
        else
        {
            //account doesn't exists
            return false;
        }
        
    }

But I dont understand how to implent it into the jquery function...