# Include Foreign Package To Read SAS Transport Files
library(foreign)

# Create Temporary File To Store Downloaded SAS Transport Files
tf <- tempfile()

# Download NHANES 1999-2000 Alcohol Questionnaire Data To Temporary File
download.file("ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/nhanes/1999-2000/ALQ.xpt", tf, mode="wb")
# Create Data Frame From Temporary File                                              
ALQ <- read.xport(tf)

# Download NHANES 2001-2002 Alcohol Questionnaire Data To Temporary File
download.file("ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/nhanes/2001-2002/ALQ_B.xpt", tf, mode="wb")
# Create Data Frame From Temporary File                                              
ALQ_B <- read.xport(tf)

# Rename Variable ALD100
names(ALQ_B)[names(ALQ_B)=="ALD100"] <- "ALQ100"

# Append Demographic Data
ALQ_4Yr <- rbind(ALQ, ALQ_B)