I applied all together 8 times. 7 times they rejected. Everytime I applied they came with the same file. Gave me the reason that I was not able to show social and economic ties with the place of residence. I had a sponsor letter from US saying while I am in States I would be an asset to her family. It was a mistake. Pay attention never go to to Embassy with such Sponsor letter.Does not matter you go for study or business or travel or visit. Finally I got it. The lady at the embassy said I do not know why but you are getting one. Shaked the hands and left. Got the visa. Ever since I am here. I am happy now that I donot need a visa anymore. Otherwise they would come back with the same file again.