Entering row value in Excel formula from cell

Hello,

I want to make an sheet that pulls text from Sheet1 into Sheet2. This is a simple use of the "=" key, but, I want to select the row this data comes from on Sheet1 with an entry into a cell on Sheet2.
eg: Sheet1 - a list of names in Column A - phone numbers in Column B
------ A --------- B --
1 Mary (111)111-1111
2 John (222)222-2222
3 Fred (333)333-3333

Sheet 2 -
------ A ---------- B --
1 1 (selected Row)

2 =Sheet1!A1 - this brings "Mary" into this cell

I want to be able to enter another row into the formula by typing its number into A1 of
Sheet 2
------ A ---------- B --
1 2 (selected Row)

2 =Sheet1!A2 - this formula brings "John" into this cell