/*******************************************************************************/
/***** POSITION METHODS ********************************************************/
/*******************************************************************************/
Position.GetPageSize = function() {
	
	var xScroll, yScroll;
	
	if (window.innerHeight && window.scrollMaxY) {	
		xScroll = window.innerWidth + window.scrollMaxX;
		yScroll = window.innerHeight + window.scrollMaxY;
	} else if (document.body.scrollHeight > document.body.offsetHeight){ // all but Explorer Mac
		xScroll = document.body.scrollWidth;
		yScroll = document.body.scrollHeight;
	} else { // Explorer Mac...would also work in Explorer 6 Strict, Mozilla and Safari
		xScroll = document.body.offsetWidth;
		yScroll = document.body.offsetHeight;
	}
	
	var windowWidth, windowHeight;
	
	if (self.innerHeight) {	// all except Explorer
		if(document.documentElement.clientWidth){
			windowWidth = document.documentElement.clientWidth; 
		} else {
			windowWidth = self.innerWidth;
		}
		windowHeight = self.innerHeight;
	} else if (document.documentElement && document.documentElement.clientHeight) { // Explorer 6 Strict Mode
		windowWidth = document.documentElement.clientWidth;
		windowHeight = document.documentElement.clientHeight;
	} else if (document.body) { // other Explorers
		windowWidth = document.body.clientWidth;
		windowHeight = document.body.clientHeight;
	}	
	
	// for small pages with total height less then height of the viewport
	if(yScroll < windowHeight){
		pageHeight = windowHeight;
	} else { 
		pageHeight = yScroll;
	}

	// for small pages with total width less then width of the viewport
	if(xScroll < windowWidth){	
		pageWidth = xScroll;		
	} else {
		pageWidth = windowWidth;
	}
	
	return [pageWidth, pageHeight, windowWidth, windowHeight];
}

Position.Center = function(obj) {
	if(!obj)
		return;
	
	var elemWidth, elemHeight, elemTop, elemLeft, winWidth, winHeight;
	
	var elemDims = Element.getDimensions(obj);
	elemWidth = elemDims.width;
	elemHeight = elemDims.height;
	
	var winDims = Position.GetPageSize();
	winWidth = winDims[0];
	winHeight = winDims[1];
	
	var elemLeft = (winWidth/2) - (elemWidth/2);
	var elemTop = (winHeight/2) - (elemHeight/2);
	
	obj.style.position = "absolute";
	obj.style.left = elemLeft+"px";
	obj.style.top = elemTop+"px";	
}