the code should be:
<?php
switch ($_SERVER["HTTP_HOST"]) {
case "searaysundancer370.com":
$key = "ABQIAAAAgwtnfPNsBdEuoMiz7NZqoBS4ZVxhru6LkDaeeOoNxAQuLVGqbxRZ7MIad5ZJjxL82oxdSH3m3LJ3uQ";
break;
case "94searaysundancer370.com":
$key = "ABQIAAAAgwtnfPNsBdEuoMiz7NZqoBToqOJDWkzYAxl4kqVz88eMNB2R6xSNBMF6R1rxfnb3YZBo47bQXUDp7g";
break;
default:
$key = "ABQIAAAAgwtnfPNsBdEuoMiz7NZqoBS4ZVxhru6LkDaeeOoNxAQuLVGqbxRZ7MIad5ZJjxL82oxdSH3m3LJ3uQ";
break;
}
?>
<script type="text/javascript" src="http://maps.google.com/maps?file=api&v=2&key=<?php echo $key; ?>">/*wagmp*/</script>
but for this code to work, your pages will need to be saved as PHP pages.