explain the "new Image();"

[mmcc128]

Currently using the "document.image s" to "preload" images - not for
future pages, but for the page being loaded. I got it from
http://www.dynamicdrive.com/dynamici...agetooltip.htm

Its a nice script - pops up an img on mouseover.

I understand that its downloading SOMETHING - but its not rendering....

THE QUESTION: How does "preloading " these images (into cache, as I have
read) affect page size, page load, etc. I cannot find anything
specific regarding this.
CODE EXAMPLE:
if (document.image s) {
var theImgs = new Array();
for (var i=0; i<messages.leng th; i++) {
theImgs[i] = new Image();
theImgs[i].src = "myimg.jpg" ;
}
}

[Joshie Surber]

mm*****@gmail.c om wrote:

Currently using the "document.image s" to "preload" images - not for
future pages, but for the page being loaded. I got it from
http://www.dynamicdrive.com/dynamici...agetooltip.htm

Its a nice script - pops up an img on mouseover.

I understand that its downloading SOMETHING - but its not rendering....

THE QUESTION: How does "preloading " these images (into cache, as I have
read) affect page size, page load, etc. I cannot find anything
specific regarding this.
CODE EXAMPLE:
if (document.image s) {
var theImgs = new Array();
for (var i=0; i<messages.leng th; i++) {
theImgs[i] = new Image();
theImgs[i].src = "myimg.jpg" ;
}
}

The images will cause the page to show the loading... gizmo in the
status bar until everything is preloaded, but if you preload in an
onload handler (rather than freestanding within script tags) the page
will display without waiting on the images to download. However, while
the images are downloading, all JS events are suspended in most
browsers. So if someone has dialup and you try to prefetch a large
image, and they mouse over a dynamic menu (for example) the menu
options won't display until the image finishes downloading. I don't
know how many browsers this affects, though.