michael@0: var currentOffset = null;
michael@0: var maxOffset = null;
michael@0: var property = "top";
michael@0: 
michael@0: var rfa = null;
michael@0: if (window.requestAnimationFrame) {
michael@0:   rfa = requestAnimationFrame;
michael@0: } else if (window.mozRequestAnimationFrame) {
michael@0:   rfa = mozRequestAnimationFrame;
michael@0: } else if (window.webkitRequestAnimationFrame) {
michael@0:   rfa = webkitRequestAnimationFrame;
michael@0: } else if (window.msRequestAnimationFrame) {
michael@0:   rfa = msRequestAnimationFrame;
michael@0: } else if (window.oRequestAnimationFrame) {
michael@0:   rfa = oRequestAnimationFrame;
michael@0: }
michael@0: 
michael@0: function animate(from, to, prop) {
michael@0:   currentOffset = from;
michael@0:   maxOffset = to;
michael@0:   if (prop) {
michael@0:     property = prop;
michael@0:   }
michael@0:   rfa(animateStep);
michael@0: }
michael@0: 
michael@0: function animateStep() {
michael@0:   if (currentOffset <= maxOffset) {
michael@0:     document.getElementById("child").style[property] = currentOffset + "px";
michael@0:     currentOffset += 10;
michael@0:     rfa(animateStep);
michael@0:   } else {
michael@0:     document.documentElement.removeAttribute("class");
michael@0:   }
michael@0: }
michael@0: 
michael@0: function toAuto(prop) {
michael@0:   if (prop) {
michael@0:     property = prop;
michael@0:   }
michael@0:   rfa(setToAuto);
michael@0: }
michael@0: 
michael@0: function setToAuto() {
michael@0:   document.getElementById("child").style[property] = "auto";
michael@0:   document.documentElement.removeAttribute("class");
michael@0: }
michael@0: 
michael@0: function fromAuto(to, prop) {
michael@0:   maxOffset = to;
michael@0:   if (prop) {
michael@0:     property = prop;
michael@0:   }
michael@0:   rfa(setFromAuto);
michael@0: }
michael@0: 
michael@0: function setFromAuto() {
michael@0:   document.getElementById("child").style[property] = maxOffset + "px";
michael@0:   document.documentElement.removeAttribute("class");
michael@0: }
michael@0: