My gross salary about 26000USD yearly. Every month, I am paying ~500 tax (both state and Federal) . I want to know how much I will get refund if I will file the tax? I live in Oklahoma, Status is single. This is my 3rd year in USA. I am from India. I am a researcher in J1 VISA. I have not received W2 form.

Fed Withholdng 3,732.
Fed MED/EE 381.87
Fed OASDI/EE 1,632.83
OK Withholdng 988.00

I am adding few more details as above, as of Dec 2009 from my pay check. Can you please inform me, how much I need to pay tax or not. How much I will get refund. Thanks

Unless you have J1 student visa, this is your third year in the U.S. You will file resident tax return.
Your federal income tax is about $2080. You will get $400 Making Work Pay Credit. So if tax withheld is more than $1680, you have a refund. J1 tax filing: Your U.S. Tax Return: The U.S. Visas