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


program PangramChecker;
 
{$APPTYPE CONSOLE}
 
uses StrUtils;
 
function IsPangram(const aString: string): Boolean;
var
  c: char;
begin
  for c := 'a' to 'z' do
    if not ContainsText(aString, c) then
      Exit(False);
 
  Result := True;
end;
 
begin
  Writeln(IsPangram('The quick brown fox jumps over the lazy dog')); // true
  Writeln(IsPangram('Not a panagram')); // false
end.