Can anyone clarify this code for me?

[admin]

Hi there,

I wanted a piece of code that would grade my quiz program i.e Highlight the correct answer in each case.
I came across the following code and it works, the trouble is I don't know excactly what it is doing?? I have traced through the code a number of times but am no wiser to its actual purpose.
A brief synopsis of the functions below would be greatly appreciated.

Thanks,


function getStyleObject(objectId) {
// cross-browser function to get an object's style object given its id
if(document.getElementById && document.getElementById(objectId)) {
// W3C DOM
return document.getElementById(objectId).style;
} else if (document.all && document.all(objectId)) {
// MSIE 4 DOM
return document.all(objectId).style;
} else if (document.layers && document.layers[objectId]) {
// NN 4 DOM.. note: this won't find nested layers
return document.layers[objectId];
} else {
return false;
}
} // getStyleObject



function changeObjectVisibility(objectId, newVisibility) {
// get a reference to the cross-browser style object and make sure the object exists
var styleObject = getStyleObject(objectId);
if(styleObject) {
styleObject.visibility = newVisibility;
return true;
} else {
//we couldn't find the object, so we can't change its visibility
return false;
}
} // changeObjectVisibility



for (i=0 ; i<41 ; i++) {
var styleObject = getStyleObject('answer'+i);
if(styleObject) styleObject.background = colour;
}