getResizedDimensions = function(img, max_width, max_height) {

	var width = img.offsetWidth - 2;
	var height = img.offsetHeight - 2;

	var x_ratio = max_width / width;
	var y_ratio = max_height / height;

	if( (width <= max_width) && (height <= max_height) ) {
	   tn_width = width;
	   tn_height = height;
	}
	else if ((x_ratio * height) < max_height) {
	   tn_height = Math.ceil(x_ratio * height);
	   tn_width = max_width;
	}
	else {
	   tn_width = Math.ceil(y_ratio * width);
	   tn_height = max_height;
	}
	var dim = new Array();
	dim[0] = tn_width;
	dim[1] = tn_height;

	return dim;
}