My friend is giving me invitation from Qatar here...

Dear Customer, 
Thanks for joining and trusting us, much appreciated!
We would like to inform you that You can obtain a visit visa to the United States known as B2 Visa, which means obtaining a visit visa and issued to people who enter the United States temporarily for entertainment and tourism, and you must stamp tourist visa or B1-B2 or B2 from the United States of America in your passport. Visit visa to the United States is maximum for six months, and you can get it through the US Embassy in your country and apply for a visa and fill out the form prepared for this and attach a white background photo then pay the application fee. The competent department will take your fingerprints and set a date for an interview in the consulate with your passport, personal photo and receipt of payment of fees attached.
In case you are applying for a B-1 / B-2 visa, you must convince the consular officer that you are eligible for a US visa in accordance with US Immigration and Nationality Act. Note that section 214 (b) of the Immigration and Nationality Act assumes that each applicant is considered an expected immigrant. Thus you must overcome this legal assumption by showing:
That your trip to the United States should be a temporary visit, such as business, entertainment, or medical treatment.
You must make it clear that you plan to stay in the US for a limited period of time.
You must prove that there are funds to cover your expenses while you are in the United States.
To have a residence outside the United States, as well as binding social and economic ties that ensure your return to your home country at the end of your visit.
you can apply through   the US Embassy in Qatar

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