-- First Cursor

-- DECLARE two variables
DECLARE @fName1 varchar(50), @lName1 varchar(50)
-- Declare cursor
DECLARE cursor1 CURSOR
FOR Select firstName, lastName FROM myTable1 INNER JOIN mytable2
-- open the cursor
OPEN cursor1
-- Fetch a row from cursor into two variables
FETCH NEXT FROM cursor1
INTO @fName1, @lName1

-- second cursor

-- DECLARE two variables
DECLARE @fName2 varchar(50), @lName2 varchar(50)
-- Declare cursor
DECLARE cursor2 CURSOR
FOR Select firstName, lastName FROM myTable3 INNER JOIN mytable4
-- open the cursor
OPEN cursor2
-- Fetch a row from cursor into two variables
FETCH NEXT FROM cursor2
INTO @fName2, @lName2

-- Now compare the @fName1 wth fName2 and then lName1 with lName2 using IF

IF @fName1 = @fName2 AND @lName = @lName

      -- DO UR TASK OF UPDATE

Hope it is helpful to u though m late