Add keypress example

simple_examples/keypress.pas

@@ -0,0 +1,24 @@
+program keypress;
+
+{#mode objfpc}{$H+}
+
+procedure KeyPress(Key: Char);
+begin
+  case upCase(Key) of
+    '0'..'9': WriteLn('Key ''', Key, ''' is numeric');
+    'A', 'E', 'I', 'O', 'U': WriteLn('Key ''', Key, ''' is a vowel');
+    'B'..'D', 'F'..'H', 'J'..'N', 'P'..'T', 'V'..'Z': 
+      WriteLn('Key ''', Key, ''' is a consonant');
+    else WriteLn('Key ''', Key, ''' is not alphanumeric');
+  end;
+end;
+  
+var s: string;
+
+begin
+  WriteLn('Press a key, then [Enter], (or [Enter] alone to finish)');
+  repeat
+    ReadLn(s);
+    if s <> '' then KeyPress(s[1]);
+  until s='';
+end.