javascript display

// Fades out and clips away the FileProgress box.
FileProgress.prototype.disappear = function () {

var reduceOpacityBy = 15;
var reduceHeightBy = 4;
var rate = 30; // 15 fps

if (this.opacity > 0) {
this.opacity -= reduceOpacityBy;
if (this.opacity < 0) {
this.opacity = 0;
}

if (this.fileProgressWrapper.filters) {
try {
this.fileProgressWrapper.filters.item("DXImageTransform.Microsoft.Alpha").opacity = this.opacity;
} catch (e) {
// If it is not set initially, the browser will throw an error.  This will set it if it is not set yet.
this.fileProgressWrapper.style.filter = "progid:DXImageTransform.Microsoft.Alpha(opacity=" + this.opacity + ")";
}
} else {
this.fileProgressWrapper.style.opacity = this.opacity / 100;
}
}

if (this.height > 0) {
this.height -= reduceHeightBy;
if (this.height < 0) {
this.height = 0;
}

this.fileProgressWrapper.style.height = this.height + "px";
}

if (this.height > 0 || this.opacity > 0) {
var oSelf = this;
setTimeout(function () {
oSelf.disappear();
}, rate);
} else {
this.fileProgressWrapper.style.display = "none";
}
};