/**
	Converts a given amount of pixels to the corresponding amount of Ems.

		var a = glesea.toEm({px: 42});

		// a ==> 2.625

	@method toEm
	@for glesea

	@param {DOM node} context The context to measure px/em
	@param {Number} px
	
	@return {Number} Amount of Ems
**/
glesea.toEm = function(options) {
	options = glesea.defaultize({
		px: 10
	}, options);

	if (!options.hasOwnProperty('context')) {
		options.context = document.querySelector('body');
	}

	var theDiv = document.createElement('div');

	theDiv.style.position = 'absolute';
	theDiv.style.left = '-99999px';
	theDiv.style.top = '-99999px';
	theDiv.style['font-size'] = '1em';
	theDiv.style.margin = 0;
	theDiv.style.padding = 0;
	theDiv.style.height = 'auto';
	theDiv.style['line-height'] = 1;
	theDiv.style.border = 0;
	theDiv.innerHTML = ' ';

	options.context.appendChild(theDiv);
	var value = theDiv.offsetHeight;

	theDiv.parentNode.removeChild(theDiv);

	return Number((options.px / value).toFixed(8));
};

/**
	Converts a given amount of Ems to the corresponding amount of Pixels.

		var a = glesea.toPx({em: 42});

		// a ==> 672

	@method toPx
	@for glesea

	@param {DOM node} context The context to measure px/em
	@param {Number} em
	
	@return {Number} Amount of pixels
**/
glesea.toPx = function(options) {
	options = glesea.defaultize({
		em: 10
	}, options);

	if (!options.hasOwnProperty('context')) {
		options.context = document.querySelector('body');
	}

	var theDiv = document.createElement('div');

	theDiv.style.position = 'absolute';
	theDiv.style.left = '-99999px';
	theDiv.style.top = '-99999px';
	theDiv.style['font-size'] = '1em';
	theDiv.style.margin = 0;
	theDiv.style.padding = 0;
	theDiv.style.height = 'auto';
	theDiv.style['line-height'] = 1;
	theDiv.style.border = 0;
	theDiv.innerHTML = ' ';

	options.context.appendChild(theDiv);
	var value = theDiv.offsetHeight;
	
	theDiv.parentNode.removeChild(theDiv);

	return Number((options.em * value).toFixed(8));
};