mr fork fork_listhotmailcom original message jim whitehead toddlers pressing play must cause music start immediately within half second toddler get causality press button multiple times sound indicating music start real soon well pressing button multiple times shouldnt change semantics like elevator button matter many times press elevator still comes floor play button needs idempotency everywhere look would ideal toddler cd player like would immediately start playing cd loaded itd mp3 player solid state storage instant wed 4 sep 2002 211150 0700 cd player ui toddlers