$(document).ready(function() {
	var thead = $('thead').height();
	var tfoot = $('tfoot').height();
	var ttable = $('html').height();
	ttable = (ttable - tfoot - thead);
	$('td.lens').attr('height',ttable);
	$('td.lens').css('height',ttable);
});
$(window).resize(function(){
	var thead = $('thead').height();
	var tfoot = $('tfoot').height();
	var ttable = $('html').height();
	ttable = (ttable - tfoot - thead);
	$('td.lens').attr('height',ttable);
	$('td.lens').css('height',ttable);
});