Under the general rule, you may be able to claim the credit if:
(1) you pay someone to care for
(2) your dependent, who is under age 13
(3) or for your spouse or dependent who is not able to care for himself or herself.
(4) you must pay these expenses so you can work or look for work.
If you think you may qualify under the general rule, I suggest you see IRS Publication 17, Your Federal Income Tax, which you can download at the IRS site at:
http://www.irs.ustreas.gov/forms_pubs/index.html. That publication will give the qualifications for the credit in detail.