This can be easily done with JavaScript or PHP... But here is the code:
HTML Code:
<body>
<table style="height: 800px; width: 100%; overflow: hidden;" align="center" border="0" cellpadding="0" cellspacing="0">
<tr><td><a href="#section1"></a>
Site Code (exactly 800px)...
<a href="#section2"></a>
Site Code (exactly 800px)...
</td></tr></table></body>
Or better with PHP:
PHP Code:
<body>
<table style="height: 100%; width: 100%; overflow: hidden;" border="0" cellpadding="0" cellspacing="0">
<tr><td style="display: <?php echo ($_GET["section"]===1)? "block;" : "none;"; ?>">
Site Code (any Length)...
</td></tr><tr><td style="display: <?php echo ($_GET["section"]===2)? "block;" : "none;"; ?>">
Site Code (any length)...
</tr></td></table></body>
The URL instead of #section1 would be ?section=1, but it's still easier and more reliable to do.
Adjust size measurements