Hello,
I am trying to create a rollover effect. When you rollover the picture a larger version of that image should pop up. Similar to www.amywoodthomas.com/room.php. My Javascript seems to work but the image does not stay up while the mouse is on the image, it stays for a second. Can someone please help me with this? I am very new to Javascript so please explain in very simple terms

var offsetfrommouse=[15,-270]; //image x,y offsets from cursor position in pixels. Enter 0,0 for no offset
var displayduration=0; //duration in seconds image should remain visible. 0 for always.
var currentimageheight = 270; // maximum image size.

if (document.getElementById || document.all){
document.write("<div id='trailimageid'>");
document.write('</div>');
}

function gettrailobj(){
if (document.getElementById)
return document.getElementById('trailimageid').style
else if (document.all)
return document.all.trailimagid.style
}

function gettrailobjnostyle(){
if (document.getElementById)
return document.getElementById('trailimageid')
else if (document.all)
return document.all.trailimagid
}


function truebody(){
return (!window.opera && document.compatMode && document.compatMode!='BackCompat')? document.documentElement : document.body
}

function showtrail(imagename){

document.onmousemove=followmouse;

newHTML = "<div style='padding: 5px; background-color: white; border: 1px solid #c28549;'>"
newHTML = newHTML + "<div align='center' style='padding: 8px 2px 2px 2px;'>";
newHTML = newHTML + "<img src='" + imagename + "' border='0'></div>";
newHTML = newHTML + '</div>';
gettrailobjnostyle().innerHTML = newHTML;
gettrailobj().display='inline';
}


function hidetrail(){
gettrailobj().innerHTML = ' ';
gettrailobj().display='none'
document.onmousemove=''
gettrailobj().left='-500px'

}

function followmouse(e){

var xcoord=offsetfrommouse[0]
var ycoord=offsetfrommouse[1]

var docwidth=document.all? truebody().scrollLeft+truebody().clientWidth : pageXOffset+window.innerWidth-15
var docheight=document.all? Math.min(truebody().scrollHeight, truebody().clientHeight) : Math.min(window.innerHeight)

//if (document.all){
// gettrailobjnostyle().innerHTML = 'A = ' + truebody().scrollHeight + '<br>B = ' + truebody().clientHeight;
//} else {
// gettrailobjnostyle().innerHTML = 'C = ' + document.body.offsetHeight + '<br>D = ' + window.innerHeight;
//}

if (typeof e != 'undefined'){
// if (docwidth - e.pageX < 200){
xcoord = e.pageX - xcoord - 230; // Move to the left side of the cursor
// } else {
// xcoord += e.pageX - xcoord;
// }
// if (docheight - e.pageY < (currentimageheight + 110)){
// ycoord += e.pageY - Math.max(0,(110 + currentimageheight + e.pageY - docheight - truebody().scrollTop));
// } else {
ycoord = e.pageY - 300;
// }

} else if (typeof window.event != 'undefined'){
// if (docwidth - event.clientX < 200){
xcoord = event.clientX + truebody().scrollLeft - xcoord - 230; // Move to the left side of the cursor
// } else {
// xcoord += truebody().scrollLeft+event.clientX
// }
// if (docheight - event.clientY < (currentimageheight + 110)){
// ycoord += event.clientY + truebody().scrollTop - Math.max(0,(110 + currentimageheight + event.clientY - docheight));
// } else {
ycoord += truebody().scrollTop + event.clientY;
// }
}

if(ycoord < 0) { ycoord = ycoord*-1; }
gettrailobj().left=xcoord+'px'
gettrailobj().top=ycoord+'px'

}