function ixixi_cm ()
{
	// display length
	var dispCm = document.getElementById('ixixi_cm').value;

	// monitor size
	var monitorSize = document.getElementById('ixixi_input').value;
	document.getElementById('ixixi_input').value = monitorSize
	
	// get inch
	var inch = (56.6797476176793579 / 1440) * dispCm * 10;
	
	// get monitor pixel size
	var monitorPixelW = screen.width;
	var monitorPixelH = screen.height;
	
	// check monitor type (normal : wide)
	var factor = 0.8;
	if (!((monitorPixelH/monitorPixelW) == (4/5) || (monitorPixelW/monitorPixelH) == (4/5)))
	{
		factor = 0.85
	}

	// monitor size multiple
	monitorSize = monitorSize * factor;
	
	// get ratio
	var ratio = monitorPixelW / monitorSize;
	
	// get pixel
	var result = Math.round(ratio * inch * 10) / 10;
	result = result + 'px';
	
	document.getElementById('ixixi_result').style.width = result;
}