function centerAndShowDiv(id){
	var dv = document.getElementById(id);
	dv.style.display='inline';
	var scrlsz = getScrollXY();
	var pgsz = getPageSize();
	dv.style.top = (scrlsz[1]+(pgsz[1]-500)/2)+'px';
	
	dv.style.left = ((pgsz[0] - 800)/2) + 'px'; 
	
}

function getScrollXY() {
  var scrOfX = 0, scrOfY = 0;
  if( typeof( window.pageYOffset ) == 'number' ) {
    //Netscape compliant
    scrOfY = window.pageYOffset;
    scrOfX = window.pageXOffset;
  } else if( document.body && ( document.body.scrollLeft || document.body.scrollTop ) ) {
    //DOM compliant
    scrOfY = document.body.scrollTop;
    scrOfX = document.body.scrollLeft;
  } else if( document.documentElement && ( document.documentElement.scrollLeft || document.documentElement.scrollTop ) ) {
    //IE6 standards compliant mode
    scrOfY = document.documentElement.scrollTop;
    scrOfX = document.documentElement.scrollLeft;
  }
  arrayPageSizeWithScroll = new Array(scrOfX,scrOfY);
  return arrayPageSizeWithScroll;
}

	function getPageSize() {
	  var myWidth = 0, myHeight = 0;
	  if( typeof( window.innerWidth ) == 'number' ) {
	    //Non-IE
	    myWidth = window.innerWidth;
	    myHeight = window.innerHeight;
	  } else if( document.documentElement && ( document.documentElement.clientWidth || document.documentElement.clientHeight ) ) {
	    //IE 6+ in 'standards compliant mode'
	    myWidth = document.documentElement.clientWidth;
	    myHeight = document.documentElement.clientHeight;
	  } else if( document.body && ( document.body.clientWidth || document.body.clientHeight ) ) {
	    //IE 4 compatible
	    myWidth = document.body.clientWidth;
	    myHeight = document.body.clientHeight;
	  }
	   return [ myWidth, myHeight ];
	}