function calculateBgImage() {
	
	defaultRatio = 0;
	defaultWidth = 1400;
	defaultHeight = 662;
	defaultRatio = defaultWidth / defaultHeight;

	dynamicRatio = 0;
	dynamicWidth = $('content').getCoordinates().width;
	dynamicHeight = $('content').getCoordinates().height;
	dynamicRatio = dynamicWidth / dynamicHeight;

	if (dynamicRatio > defaultRatio) {

		dynamicHeight_img = dynamicWidth / defaultRatio;
		trueTop = Math.round(Math.abs((dynamicHeight_img - dynamicHeight) / 2));
		
		$('content_image').setStyles({
			'left':'0',
			'top':'-'+trueTop+'px',
			'width':'100%',
			'height':'auto'
		});
		
	}else{
		
		dynamicWidth_img = dynamicHeight * defaultRatio;
		trueLeft = Math.round(Math.abs((dynamicWidth_img - dynamicWidth) / 2));
		
		$('content_image').setStyles({
			'left':'-'+trueLeft+'px',
			'top':'0',
			'width':'auto',
			'height':'100%'
		});
	}
}


window.addEvent('resize', calculateBgImage);