// Scrollable Window Script
// Written by Francois Simard (francois79@gmail.com)
// You may use this script as long as you keep all comments.
var mouseDown = false;
var xSpace, ySpace;

// Mouse Down Event
function Mdown(e)
{
	var element = "";
	var yPos;
	// Get the mouse position and the id of the selected object
	if(e)
	{
		element = e.target.id;
		//xPos = e.pageX;
		yPos = e.pageY;
	}
	else
	{
		element = window.event.srcElement.id;
		//xPos = window.event.clientX + document.body.scrollLeft;
		yPos = window.event.clientY + document.body.scrollTop;
	}

	// if the cursor has been selected
	if(element == "cursor")
	{
		//xSpace = xPos - cursor.offsetLeft;
		ySpace = yPos - cursor.offsetTop;
		mouseDown = true;
	}
}

//Mouse Up Event
function Mup(e)
{
	mouseDown = false;
}

// Mouse Move Event
function MM(e)
{
	if(mouseDown)
	{
		var yPos = 0;
		if (!e) var e = window.event;

		if (e.pageY)
			yPos = e.pageY;
		else if (e.clientY)
			yPos = e.clientY + document.body.scrollTop;

		var newPos = yPos - ySpace;
		if(newPos < bar.offsetTop)
			newPos = bar.offsetTop;
		else if((newPos + cursor.offsetHeight) > (bar.offsetTop + bar.offsetHeight))
			newPos = (bar.offsetTop + bar.offsetHeight) - cursor.offsetHeight;
			
		cursor.style.top = newPos;
		//alert( 'cursor:'+(newPos - bar.offsetTop) + "\n" + (contentHeight * (newPos - bar.offsetTop)) / barHeight);
		content.style.top = -1 * ((contentHeight * (newPos - bar.offsetTop)) / barHeight);
		return false;
	}
}

document.onmousedown = Mdown;
document.onmouseup   = Mup;
document.onmousemove = MM;