Canvas size less than 100%

How do I get the exported game to show up as a percentage of the window width instead of defaulting to "full?"

I want my canvas to be 53% of the width of the window, and to resize vertically, keeping the correct aspect ratio.

I tried changing the code in the html file, but it doesn't want to listen - it just keeps resetting to full size.

		jQuery(window).resize(function() {
			var theCanvas = document.getElementById("c2canvas");
			var theWidth = window.innerWidth * .53;
			var theHeight = theWidth * 224/256;
			
			
			cr_sizeCanvas(theWidth, theHeight);
			theCanvas.setAttribute('width', theWidth);
			theCanvas.setAttribute('height', theHeight);
			document.write(window.innerWidth);
			
		});[/code:16x99oy0]

Try using the Sytem object set WindowWidth width/2.