Malfunctioning of Wordpress Admin Cannot Access wp-admin

Please I need help. I worked on a blog for a client and he did some work on it that resulted in the malfunctioning of the blog. Now I cannot access the dashboard of the blog what can I do?

May be he change the url of the blog go to phpmyadmin and open the table settings and see exact your url's what you are using .. like i am on localhost/wordpress a row in setting table which will show the exact url if the url not matching please change it.