var currentPage = 1;
var pageHeight = 70;
var currentTop = 0;
var newTop = 0;
var overTop = 0;
var overThrow = 10;
var stepSpeed = 30;
var moveReady = true;
var overThrowReturnTimes = 0;
var overThrowSteps = [];
var overThrowTrack = [];
var multiPageMove = [];

function getObjID(objID){
	if (document.getElementById){
		return document.getElementById(objID);
	}else if (document.all){
		tempVar="document.all."+objID;
		return tempVar;
	}else{
		return false;
	}
}

function startMovePage(objID,direction, imagePages){
	overThrowTrack = [];
	currentTop = (getObjID(objID).style.top.replace("px","")*1);
	if(moveReady){
		moveReady = false;
		if(direction=="moveForward" && currentPage < imagePages){
			currentPage++;
			if(currentPage==imagePages){
				getObjID("moveForward").style.display='none';
				getObjID("blankForward").style.display='block';
			}
			getObjID("moveBack").style.display='block';
			getObjID("blankBack").style.display='none';
			newTop = currentTop - pageHeight;
			overTop = currentTop - pageHeight - overThrow;
		}else if(direction=="moveBack" && currentPage > 1){
			currentPage--;
			if(currentPage==1){
				getObjID("moveBack").style.display='none';
				getObjID("blankBack").style.display='block';
			}
			getObjID("moveForward").style.display='block';
			getObjID("blankForward").style.display='none';
			newTop = currentTop + pageHeight;
			overTop = currentTop + pageHeight + overThrow;
		}else{
			return
		}
		multiPageMove[objID]=window.setInterval('movePage(\''+objID+'\','+newTop+','+overTop+')',stepSpeed);
	}
}

function movePage(objID,newTop,overTop){
	currentTop = (getObjID(objID).style.top.replace("px","")*1);
	if(currentTop > overTop){
		var moveHere = Math.floor(currentTop+(overTop-currentTop)/3);
		getObjID(objID).style.top = moveHere+'px';
		if(currentTop <= newTop){
			var arrayLen = overThrowTrack.length;
			overThrowTrack[arrayLen] = moveHere;
		} 
	}else if(currentTop < overTop){
		var moveHere = Math.ceil(currentTop+(overTop-currentTop)/3);
		getObjID(objID).style.top = moveHere+'px';
		if(currentTop >= newTop){
			var arrayLen = overThrowTrack.length;
			overThrowTrack[arrayLen] = moveHere;
		}
	}else{
		clearInterval(multiPageMove[objID]);
		overThrowTrack.reverse();
		loadThrowSteps();
		overThrowReturnTimes = 0;
		multiPageMove[objID]=window.setInterval('overThrowReverse(\''+objID+'\',true)',stepSpeed*.75);
	}
}

function overThrowReverse(objID,again){
	if(again){
		if(overThrowReturnTimes < overThrowSteps.length){
			currentTop = (getObjID(objID).style.top.replace("px","")*1);
			getObjID(objID).style.top = (currentTop+overThrowSteps[overThrowReturnTimes])+'px';
			overThrowReturnTimes++;
		}else{
			getObjID(objID).style.top = newTop+'px';
			overThrowReturnTimes = 0;
			clearInterval(multiPageMove[objID]);
			overThrowTrack.reverse();
			multiPageMove[objID]=window.setInterval('overThrowAgain(\''+objID+'\')',stepSpeed*.50);
		}
	}else{
		if(overThrowReturnTimes > 1){
			currentTop = (getObjID(objID).style.top.replace("px","")*1);
			getObjID(objID).style.top = (currentTop-overThrowSteps[overThrowReturnTimes])+'px';
			overThrowReturnTimes--;
		}else{
			getObjID(objID).style.top = newTop+'px';
			overThrowReturnTimes = 0;
			clearInterval(multiPageMove[objID]);
			moveReady = true;
		}
	}
}

function overThrowAgain(objID){
	if(overThrowReturnTimes < Math.floor(overThrowSteps.length)){
		currentTop = (getObjID(objID).style.top.replace("px","")*1);
		getObjID(objID).style.top = (currentTop+overThrowSteps[overThrowReturnTimes])+'px';
		overThrowReturnTimes++;
	}else{
		clearInterval(multiPageMove[objID]);
		overThrowReturnTimes--;
		multiPageMove[objID]=window.setInterval('overThrowReverse(\''+objID+'\',false)',stepSpeed*.25);
	}
}

function loadThrowSteps(){
	for(var i=0;i<overThrowTrack.length-1;i++){
		overThrowSteps[i] = (overThrowTrack[i] - overThrowTrack[i+1])*-1;
	}
}

//Hide album image while loading
function imgLoadingLnk(url,objID){
	getObjID(objID).style.display="none";
	if(document.images){
		var pic= new Image(); 
		pic.src=url;
		if(pic.complete){
			getObjID(objID).src=url;
			getObjID(objID).style.display="block";
		}else{
			pic.onload= function(){
				getObjID(objID).src=url;
				getObjID(objID).style.display="block";
			}
		}
	}
}