function font_size() {
	var font_size = document.getElementById('article_content').style.fontSize;
	//alert(font_size);
	var line_height = document.getElementById('article_content').style.lineHeight;
	//alert(line_height);
	if (font_size == '100%' && line_height == '18px') {
		font_size = '130%';
		line_height = '23px';
	}
	else {
		font_size = '100%';
		line_height = '18px';
	}
	document.getElementById('article_content').style.fontSize = font_size;
	document.getElementById('article_content').style.lineHeight = line_height; 
}