How to call functions when a key changes it's state

Dependencies:   Hotboards_keypad mbed

Revision:
0:a2b95a8cb722
diff -r 000000000000 -r a2b95a8cb722 mbed.bld
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Tue Mar 08 20:46:03 2016 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/mbed/builds/87f2f5183dfb
\ No newline at end of file