var ie = document.getElementById && document.all;
        var moz = document.getElementById && !document.all;

        function setVAlign() {
                var black_block = document.getElementById('black_block');
                //var grey_block = document.getElementById('grey_block');
                var content_block = document.getElementById('content_block');
                var content_wrapper = document.getElementById('content_wrapper');
                var footer_block = document.getElementById('footer_block');
                //holder.style.height = document.body.clientHeight + "px";

                if (ie) {
                        //alert( window.screenTop );
                        black_block.style.height = screen.availHeight - window.screenTop - 30 + "px";
                        //grey_block.style.height = screen.availHeight - window.screenTop - 30 + "px";
                        content_wrapper.style.height = screen.availHeight - window.screenTop - 30 + "px";
                        footer_block.style.top = screen.availHeight - window.screenTop - 110 + "px";
                        //var newTop = screen.availHeight - window.screenTop - 30;
                        //content_block.style.position = 'absolute';
                        //content_block.style.top = (newTop - 425)/2 + 'px';
//                      alert( black_bloc//k.style.height );
//                      alert( screen.availHeight - window.screenTop );
//                      alert( document.body.clientHeight );
//                      alert( screen.availHeight );
//                      alert( window.screenTop );

                } else if (moz) {
                        black_block.style.height = window.innerHeight + "px";
                        footer_block.style.top = (window.innerHeight - 80) + "px";
                        //grey_block.style.height = window.innerHeight + "px";
                        content_wrapper.style.height = window.innerHeight + "px";
                        //alert( window.innerHeight );
                        //alert( screen.availHeight );
                }

        }