function showDescription(id, opacStart, opacEnd, millisec) {
   //speed for each frame
    var object = document.getElementById(id).style;
    var speed = Math.round(millisec / 100);
    var timer = 0;

    //determine the direction for the blending, if start and end are the same nothing happens
    if(opacStart > opacEnd)
	{
		for(i = opacStart; i >= opacEnd; i--)
		{
            setTimeout("changeOpac(" + i + ",'" + id + "',"+opacStart+","+opacEnd+")",(timer * speed));
            timer++;
		}
		
	} 
	else if(opacStart < opacEnd) {
		//showing the div
		document.getElementById(id).style.display='inline';
		
		var fTop = (screen.height)/1.87;
		var fLeft = ((screen.width)-640)/2;
		if(navigator.appName == "Netscape") {
			document.getElementById(id).style.top = window.pageYOffset+fTop;
			document.getElementById(id).style.left = window.pageXOffset+fLeft;
		} else {
			document.getElementById(id).style.top = document.body.scrollTop+fTop;
			document.getElementById(id).style.left = document.body.scrollLeft+fLeft;
		}
		
        for(i = opacStart; i <= opacEnd; i++)
            {
            setTimeout("changeOpac(" + i + ",'" + id + "',"+opacStart+","+opacEnd+")",(timer * speed));
            timer++;
        }
    }
}

//change the opacity for different browsers
function changeOpac(opacity, id, opacStart, opacEnd) {
	var object = document.getElementById(id).style;
    object.opacity = (opacity / 100);
    object.MozOpacity = (opacity / 100);
    object.KhtmlOpacity = (opacity / 100);
    object.filter = "alpha(opacity=" + opacity + ")";
	//hiding the div
	if(opacStart > opacEnd && opacity==0)
	{
		document.getElementById(id).style.display='none';	
	}
}