// fdrlib.js - version 1.0
// FadeDropRaise Library for Javascript
// Nick O'Neill 2005

function fadeElementIn(id,time,begin){
   // <a href="javascript:fadeElementIn(myelementid,0.3)">fade in!</a>
   // ---- SET THESE IN YOUR SCRIPTS
   // id is the id of the element you're fading
   // time is the amount of time you'd like your element to spend fading in (try 0.3)
   
   // ---- DON'T SET THESE IN YOUR SCRIPTS
   // begin is the start time of your fade - it will be set automatically when the function is called
       
   var elem = getByID(id);
   
   var current = new Date().getTime();
   if (typeof(begin) == "number"){}
   else {begin = new Date().getTime()}
   
   var timeDiff = (current - begin) / 1000; // /
   
   if (timeDiff < time){
      
      var boxOpacity = (timeDiff/time)*(timeDiff/time);

      setOpacity(elem.id,boxOpacity);
   
      setTimeout("fadeElementIn(\'"+id+"\',"+time+","+begin+")",16);
   } else {setOpacity(elem.id,.99);return}
}

function fadeElementOut(id,time,begin){
   // <a href="javascript:fadeElementOut(myelementid,0.3)">fade out!</a>
   
   // ---- SET THESE IN YOUR SCRIPTS
   // id is the id of the element you're fading
   // time is the amount of time you'd like your element to spend fading out (try 0.3)
   
   // ---- DON'T SET THESE IN YOUR SCRIPTS
   // begin is the start time of your fade - it will be set automatically when the function is called

   var elem = getByID(id);
   
   var current = new Date().getTime();
   if (typeof(begin) == "number"){}
   else {begin = new Date().getTime()}
   
   var timeDiff = (current - begin) / 1000; // /
   
   if (timeDiff < time) {

      var boxOpacity = .99-((timeDiff/time)*(timeDiff/time));

      setOpacity(elem.id,boxOpacity);
   
      setTimeout("fadeElementOut(\'"+id+"\',"+time+","+begin+")",16);
   } else {setOpacity(elem.id,0);return}
}

function raiseElementUp(id,ascent,time,begin,modAscent,topOrig){
   // <a href="javascript:raiseElementUp(myelementid,-100,0.4)">raise up!</a>
   
   // ---- SET THESE IN YOUR SCRIPTS
   // id is the id of the element you're raising
   // ascent is the amount of pixels the element will lift
   // time is the amount of time in seconds that you'd like your element to spend getting to it's final position (try 0.4)
   
   // ---- DON'T SET THESE IN YOUR SCRIPTS
   // begin is the start time of your raise - it will be set automatically when the function is called
   // modAscent is a used in calculating distance and should not be set when calling
   // topOrig is the original 'top' value of the element as set by setTop() or your own code

   var elem = getByID(id);
   
   if (elem.style.top == ""){setTop(elem.id,0)}
   if (typeof(topOrig) == "undefined"){topOrig = antipixel(elem.style.top)}
   var current = new Date().getTime();
   
   if (typeof(begin) != "number"){begin = new Date().getTime()}

   var timeDiff = (current - begin) / 1000; // /
   
   if (timeDiff < time) {
      var topPx = topOrig+(ascent*((timeDiff/time)*(timeDiff/time)));
      
      elem.style.top = pixel(topPx);
      setTimeout("raiseElementUp(\'"+id+"\',"+ascent+","+time+","+begin+","+modAscent+","+topOrig+")",16);

   } else {setTop(elem.id,topOrig+ascent);return}
}

function dropElementDown(id,decent,time,begin,modDecent,topOrig){
   // <a href="javascript:dropElementDown(myelementid,100,0.4)">drop down!</a>
   
   // ---- SET THESE IN YOUR SCRIPTS
   // id is the id of the element you're dropping
   // decent is the amount of pixels the element will drop
   // time is the amount of time in seconds that you'd like your element to spend getting to it's final position (try 0.4)
   
   // ---- DON'T SET THESE IN YOUR SCRIPTS
   // begin is the start time of your drop - it will be set automatically when the function is called
   // modDecent is a used in calculating distance and should not be set when calling
   // topOrig is the original 'top' value of the element as set by setTop() or your own code
   
   var elem = getByID(id);

   if (elem.style.top == ""){setTop(elem.id,0)}
   if (typeof(topOrig) == "undefined"){topOrig = antipixel(elem.style.top)}
   var current = new Date().getTime();

   if (typeof(begin) != "number"){begin = new Date().getTime()}

   var timeDiff = (current - begin) / 1000; // /

   if (timeDiff < time) {
      var topPx = topOrig-(decent*((timeDiff/time)*(timeDiff/time)));
      
      elem.style.top = pixel(topPx);
      setTimeout("raiseElementUp(\'"+id+"\',"+decent+","+time+","+begin+","+modDecent+","+topOrig+")",16);

   } else {setTop(elem.id,topOrig-decent);return}
}

function setOpacity(id,opacity){
   var toSet = getByID(id);
   
   if (toSet.style.MozOpacity != null){toSet.style.MozOpacity = opacity;}
   if (toSet.style.opacity != null){toSet.style.opacity = opacity;}
   if (toSet.style.filter != null){toSet.style.filter = "progid:DXImageTransform.Microsoft.Alpha(opacity="+(opacity*100)+")";}
}
function setTop(id,top){
   getByID(id).style.position = 'relative';
   getByID(id).style.top = pixel(top);
}
function getByID(n){
	var d = window.document;
	if (d.getElementById)
		return d.getElementById(n);
	else if (d.all)
		return d.all[n];
}
function pixel(px){
   return px+"px";
}
function antipixel(px){
   return parseInt(px.replace(/px/,''));
}