goheadfixed.js

function goheadfixed(classtable) {
	
	if($(classtable).length) {
	
		$(classtable).wrap('<div class="fix-inner"></div>'); 

		$('.fix-inner').wrap('<div class="fix-outer" style="position:relative; margin:auto;"></div>');
		$('.fix-outer').append('<div class="fix-head"></div>');
		$('.fix-head').prepend($('.fix-inner').html());
		$('.fix-head table').find('caption').remove();
		$('.fix-head table').css('width','100%');
	
		$('.fix-outer').css('width', $('.fix-inner table').outerWidth(true)+'px');
		$('.fix-head').css('width', $('.fix-inner table').outerWidth(true)+'px');
		$('.fix-head').css('height', $('.fix-inner table thead').height()+'px');
	
		// If exists caption, calculte his height for then remove of total
		var hcaption = 0;
		if($('.fix-inner table caption').length != 0)
			hcaption = parseInt($('.fix-inner table').find('caption').height()+'px');

		// Table's Top
		var hinner = parseInt( $('.fix-inner').offset().top );

		// Let's remember that <caption> is the beginning of a <table>, it mean that his top of the caption is the top of the table
		$('.fix-head').css({'position':'absolute', 'overflow':'hidden', 'top': hcaption+'px', 'left':0, 'z-index':100 });
		
		$(window).scroll(function () {
			var vscroll = $(window).scrollTop();

			if(vscroll >= hinner + hcaption)
				$('.fix-head').css('top',(vscroll-hinner)+'px');
			else
				$('.fix-head').css('top', hcaption+'px');
		});
	
		/*	If the windows resize	*/
		$(window).resize(goresize);
	}
}

function goresize() {
	$('.fix-head').css('width', $('.fix-inner table').outerWidth(true)+'px');
	$('.fix-head').css('height', $('.fix-inner table thead').height()+'px');
	hinner = parseInt( $('.fix-inner').offset().top );
}