If a character does a charge attack as a standard action and gets interrupted along the way such that the charging distance is cut short -- say, a fighter with combat superiority lands an opportunity attack, or difficult terrain pops up from an immediate interrupt power -- then would you rule the charging character may declare the "charge" attempt was instead now just a Move action and the PC can take an available standard action (like attacking something else within reach)? Or would you rule the standard action was made and the PC could only finish up with Move and/or Minor actions that turn?