Pangram checker

You are encouraged to solve this task according to the task description, using any language you may know.
A pangram is a sentence that contains all the letters of the English alphabet at least once.

For example:   The quick brown fox jumps over the lazy dog.



Task

Write a function or method to check a sentence to see if it is a   pangram   (or not)   and show its use.



Related tasks

   determine if a string has all the same characters
   determine if a string has all unique characters


checkPangram <- function(sentence){
  my.letters <- tolower(unlist(strsplit(sentence, "")))
  is.pangram <- all(letters %in% my.letters)
 
  if (is.pangram){
    cat("\"", sentence, "\" is a pangram! \n", sep="")
  } else {
    cat("\"", sentence, "\" is not a pangram! \n", sep="")
  }
}
 