Opening excel CSV file in R

Hi,

So I have everything written out. I used R-studio (same as R console
but with an IDE) and I had no trouble calling upon and opening the csv
file for computation.

However, when I try to run my code in plain old R, it says that the
file could not be located. Heres my code:

func<- function(filename, int) {
   Data<- read.csv("sample.csv", header = TRUE)
   attach(Data, warn.conflicts = FALSE)
   ...........
   ..........
}

I made sure that sample file was in the same directory.

I even tried
inputting the entire file location "C:\Users..."

Please help. Thanks