Why does the removal of "+-" cause the whole function to not work ?
Code is as shown below.

	$('p:first').toggle(function() {
	$(this).animate({'height':'+=150px'}, 2000, 'linear');
	}, function() {
	$(this).animate({'height':'-=150px'}, 2000, 'swing');
	});
Why does the removal of "+-" cause the whole function to not work ?
===

Code is as shown below.

	$('p:first').toggle(function() {
	$(this).animate({'height':'+=150px'}, 2000, 'linear');
	}, function() {
	$(this).animate({'height':'-=150px'}, 2000, 'swing');
	});