function showBox(){
		    $('overlay').show();
		    center('box');
		    return false;
		}
		
		function hideBox(){
		    $('box').hide();
		    $('overlay').hide();
		    return false;
		}
		
		function center(element){
		    try{
		        element = $(element);
		    }catch(e){
		        return;
		    }
		
		    var my_width  = 0;
		    var my_height = 0;
		
		    if ( typeof( window.innerWidth ) == 'number' ){
		        my_width  = window.innerWidth;
		        my_height = window.innerHeight;
		    }else if ( document.documentElement && 
		             ( document.documentElement.clientWidth ||
		               document.documentElement.clientHeight ) ){
		        my_width  = document.documentElement.clientWidth;
		        my_height = document.documentElement.clientHeight;
		    }
		    else if ( document.body && 
		            ( document.body.clientWidth || document.body.clientHeight ) ){
		        my_width  = document.body.clientWidth;
		        my_height = document.body.clientHeight;
		    }
		
		    element.style.position = 'absolute';
		    element.style.zIndex   = 99;
		
		    var scrollY = 0;
		
		    if ( document.documentElement && document.documentElement.scrollTop ){
		        scrollY = document.documentElement.scrollTop;
		    }else if ( document.body && document.body.scrollTop ){
		        scrollY = document.body.scrollTop;
		    }else if ( window.pageYOffset ){
		        scrollY = window.pageYOffset;
		    }else if ( window.scrollY ){
		        scrollY = window.scrollY;
		    }
		
		    var elementDimensions = Element.getDimensions(element);
		
		    var setX = ( my_width  - elementDimensions.width  ) / 2;
		    var setY = ( my_height - elementDimensions.height ) / 2 + scrollY;
		
		    setX = ( setX < 0 ) ? 0 : setX;
		    setY = ( setY < 0 ) ? 0 : setY;
		
		    element.style.left = setX + "px";
		    element.style.top  = setY + "px";
		
		    element.style.display  = 'block';
		}