//
    // getPageScroll()
    // Returns array with x,y page scroll values.
    // Core code from - quirksmode.org
    //
    function getPageScroll() {

        var yScroll;

        if (self.pageYOffset) {
            yScroll = self.pageYOffset;
        } else if (document.documentElement && document.documentElement.scrollTop){	 // Explorer 6 Strict
            yScroll = document.documentElement.scrollTop;
        } else if (document.body) {// all other Explorers
            yScroll = document.body.scrollTop;
        }

        arrayPageScroll = new Array('',yScroll)
        return arrayPageScroll;
    }

    //
    // getPageSize()
    // Returns array with page width, height and window width, height
    // Core code from - quirksmode.org
    // Edit for Firefox by pHaez
    //
    function getPageSize() {

        var xScroll, yScroll;

        if (window.innerHeight && window.scrollMaxY) {
            xScroll = document.body.scrollWidth;
            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
            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 = windowWidth;
        } else {
            pageWidth = xScroll;
        }

        arrayPageSize = new Array(pageWidth,pageHeight,windowWidth,windowHeight);
        return arrayPageSize;
    }


    function getParentPos(obj) {
       var curleft = curtop = 0;
       if (obj.offsetParent) {
          while (obj = obj.offsetParent) {
             curleft += obj.offsetLeft
             curtop += obj.offsetTop
          }
       }
       return [curleft,curtop];
    }


    function showCenter(id) {
        var pageSize = getPageSize();
        var pageScroll = getPageScroll();

        var element = document.getElementById(id);

        element.style.visibility = 'hidden';
        element.style.display = 'block';

        var parentPos = getParentPos(element);

        element.style.left = (pageScroll[0] + (pageSize[2] - element.offsetWidth) / 2 - parentPos[0]) + 'px';
        element.style.top = (pageScroll[1] + (pageSize[3] - element.offsetHeight) / 2 - parentPos[1]) + 'px';

        element.style.visibility = 'visible';
        return false;
    }

    function hide(id) {
        document.getElementById(id).style.display = 'none';
        return false;
    }