字符串替换？

function fn(){
		image_src = $('.details-text2 img');
		for(var i=0;i<image_src.length;i++){
			str = image_src[i].getAttribute('src');	
			var str2 = str.replace(/\/Public\/Static\/ueditor\/php\/upload\/image/g,'\/upload/portal');
			$('.details-text2 img:eq('+i+')').attr('src',str2);
		}
		fun();
	}