visitor visa,help

[karusmle]

i would like to know that if i get a visa for three months,i.e on may,june or july 2006 ,is it necessary that i have to be in US in may itself or can i get inside the US in june or july ,plz answer me ,this may be a silly question to u but i don't know anything abt visa and i really need ur help to plan my studies.
i m a doctor ,and i heard that for doctors its really tough to get the visa ,is it true?

[manishc]

You can enter US anytime during the validity of the visa. And then your stay period gets determined at your Port of Entry (POE).