I have use the "login" define as a field in cookie. Since I can;t any problem in my code, in addition, the fucking browser would report and compile normally for the programmer, Damn! (Once again, thanks to Firefox) With Firefox, I can find the bug in the line which define the field name for the "login" field.I use the "name" instead of "login" everything run smoothly. What the hell! Correct code: document.cookie = "name="+userName + expires; If u guys want to read the contains in the cookies, please use Firefox. (Camino in Mac OS X). Netscape is another choice as well. Safari is another choice in Mac OS X as we.. Once again, Microsoft Internet Explorer is loser. It can't tell me what's wrong with my codes. What's right in my cookies. Looking forward to see the IE will disappear ASAP.