Script JS center vertical window - on center of a div

center.vertical.element.js

/** Center the browser vertically on the game board */
	var centerBrowserGameBoard = function()
	{
		var w_height = $j(window).height();
		var table_top = $j('#div').offset().top;
		var table_height = $j('#div').height(); 
        
		//if no need to scroll - the table is visible
		if (!force && w_height > (table_top + table_height))
		{
			return false;
		}
     
		$j(document).scrollTop(
			//go to middle
			table_top + table_height / 2
			//now go up half of window
		   - w_height / 2
		);
	}