$(document).ready(function()
{
	$('.switch').mouseenter(function()
	{
		var thisElem=$(this).attr('id');
		if(!$('#'+thisElem+'_over').attr('background-image'))
		{
			switch (thisElem)
			{
				case 'mb':
					var bgimg='mother_roll.png';
				break;
				case 'sp':
					var bgimg='sport_roll.png';
				break;
				case 'ch':
					var bgimg='children_roll.png';
				break;
				case 'wh':
					var bgimg='what_is_roll.png';
				break;
				case 'cr':
					var bgimg='cranial_roll.png';
				break;
			}
			$('#'+thisElem+'_over').css('background-image', 'url("assets/images/'+bgimg+'")');
		}
		$('#'+thisElem+'_over').removeClass('hide');
		var childObject=$('#'+thisElem+'_over').children('.block_txt');
		$(childObject).css('top',(($('#'+thisElem+'_over').height()/2)-($(childObject).height()/2))+'px');
	});
	$('.overlay').mouseleave(function()
	{
		$(this).addClass('hide');
	});
});