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


 
  [ dup char A char [ within
    swap char a char { within
    or ]                        is letter  ( c --> b )
 
  [ 0 26 of swap witheach
      [ dup letter iff
          [ 1 unrot lower
            char a - poke ]
        else drop ]
    0 swap find 26 = ]          is pangram ( $ --> b )
 
  $ "This is a sentence." pangram echo cr                     ( 0 )
  $ "The five boxing wizards jumped quickly." pangram echo cr ( 1 )
 