// Define the BusyBox class (function)
function BusyBox(instanceVarName, imageCount, imagePrefix, imageSuffix, imageDelay)
{
 // Initialize object
 this.ImageCount = imageCount;
 this.CurrentFrame = 0;
 this.ImageWidth = 0;
 this.ImageHeight = 0;
 this.ImagePrefix = imagePrefix;
 this.ImageSuffix = imageSuffix;
 this.ImageDelay = imageDelay; // milliseconds to display each frame
 this.Enabled = true;
 this.DivID = "BusyBoxDiv";
 this.ImgID = "BusyBoxImg";
 
 // Retain the name of the instantiated object variable so that we 
 // can animate using the setTimeout statement.
 this.instanceVarName = instanceVarName;

 // Initialize to null. Allows us to stop the animation with clearTimeout(), 
 // should we ever want to.
 this.timeout_id = null;
 
 // Cache (pre-load) images
 this.CacheImages();
}

BusyBox.prototype.CacheImages = function()
{
 // Instantiate the array to store the image references
 this.Images = new Array(this.ImageCount);
 
 // Load all the images to cache into the aniframes array
 for(var i = 0; i < this.ImageCount; i++)
 {
 this.Images[i] = new Image();
 this.Images[i].src = this.ImagePrefix + i + this.ImageSuffix;
 }
}

BusyBox.prototype.Animate = function()
{
 // Display the current frame
 document.getElementById(this.ImgID).src = this.Images[this.CurrentFrame].src;
 // Increment the frame counter
 this.CurrentFrame = (this.CurrentFrame + 1)%this.ImageCount;
 // Display the next frame in imageDelay milliseconds
 this.timeout_id = setTimeout(this.instanceVarName + ".Animate();", this.ImageDelay);
}

BusyBox.prototype.StopAnimate = function()
{
 this.timeout_id = null;
}

BusyBox.prototype.Hide = function()
{
 div = document.getElementById(this.DivID);
 div.style.visibility = "hidden";
}

// This function displays the busy dialox box to the user. This function centers the 
// busy dialog box, makes it visible, and starts the animation.
// This function will typically be called by the body event: 
// "busyBox.Show();" >
BusyBox.prototype.Show = function()
{
 if (this.Enabled) 
 {
 // Find the BusyBox div tag
 div = document.getElementById(this.DivID);
 
 // Center the BusyBox in the window regardless of the scroll positions
 myLeft = ((document.body.clientWidth - div.clientWidth) / 2) + document.body.scrollLeft;
if (document.body.clientWidth > "1000") {
 myTop = ((document.body.clientHeight - div.clientHeight) / 2) + document.body.scrollTop;
 } else {
 myTop = ((document.body.clientHeight - div.clientHeight) / 1.2) + document.body.scrollTop;
}
 // Position and show the busy box
 div = document.getElementById(this.DivID);
 div.style.top = myTop;
 div.style.left = myLeft;
 div.style.visibility = 'visible';
 
 // Start the animation
 this.Animate();
 }
}