Javascript实例教程(5) 在一个表单中设置和检查Cookies

Cookie是一小段由浏览器储存起来帮助识别用户身份的信息。在一个表单中设置和检查Cookies的实现需要两个文件来完成。第一个文件为cookie1.html，这个文件需要有一些机理（下面例子的一个按钮）来检查是否有一个Cookie存在，然后再重定向至表单网页或者文档下载网页。而第二个文件，即表单网页（cookie2.html），也是和重要的因为你将要在上面使用一点点JavaScript来设置Cookie，这个设置是在提交表单之前做的。下面给出这文件

第一个文件（cookie1.html）

%26lt;HTML%26gt;

%26lt;HEAD%26gt;

%26lt;SCRIPT LANGUAGE="JavaScript"%26gt;

%26lt;!--

function cookieRedirect(hasCookieURL, noCookieURL)

{

var currentCookie = document.cookie;


if (currentCookie.indexOf("formcomplete=yes") != -1) {

window.location = hasCookieURL;

} else {

window.location = noCookieURL;

}

}

// --%26gt;

%26lt;/SCRIPT%26gt;

%26lt;/HEAD%26gt;

%26lt;BODY%26gt;

%26lt;FORM NAME="docdownload"%26gt;

%26lt;INPUT TYPE="BUTTON" VALUE="Download document"

onClick="cookieRedirect('doc.html', 'cookie2.html')"%26gt;

%26lt;/FORM%26gt;

%26lt;/BODY%26gt;

%26lt;/HTML%26gt;
第二个文件（cookie2.html ） %26lt;HTML%26gt;

%26lt;HEAD%26gt;

%26lt;SCRIPT LANGUAGE="JavaScript"%26gt;

%26lt;!--

function sendForm(objForm)

{

cookieExpires = "Saturday, 01-Jan-03 00:00:00 GMT";

document.cookie = "formcomplete=yes; path=/";

// objForm.submit();

}

// --%26gt;

%26lt;/SCRIPT%26gt;

%26lt;/HEAD%26gt;

%26lt;BODY%26gt;

%26lt;FORM ACTION="test.html" NAME="info"%26gt;

%26lt;TABLE%26gt;

%26lt;TR%26gt;

%26lt;TD%26gt;First name%26lt;/TD%26gt;

%26lt;TD%26gt;%26lt;INPUT TYPE="TEXT" NAME="firstname"%26gt;%26lt;/TD%26gt;

%26lt;/TR%26gt;

%26lt;TD%26gt;Last name%26lt;/TD%26gt;

%26lt;TD%26gt;%26lt;INPUT TYPE="TEXT" NAME="lastname"%26gt;%26lt;/TD%26gt;

%26lt;/TR%26gt;

%26lt;TR%26gt;

%26lt;TD%26gt;Address%26lt;/TD%26gt;

%26lt;TD%26gt;%26lt;INPUT TYPE="TEXT" NAME="address"%26gt;%26lt;/TD%26gt;

%26lt;/TR%26gt;

%26lt;TR%26gt;

%26lt;TD%26gt;City%26lt;/TD%26gt;

%26lt;TD%26gt;%26lt;INPUT TYPE="TEXT" NAME="city"%26gt;%26lt;/TD%26gt;

%26lt;/TR%26gt;

%26lt;TR%26gt;

%26lt;TD%26gt;State%26lt;/TD%26gt;

%26lt;TD%26gt;%26lt;INPUT TYPE="TEXT" NAME="state"%26gt;%26lt;/TD%26gt;

%26lt;/TR%26gt;

%26lt;TR%26gt;

%26lt;TD%26gt;Zip%26lt;/TD%26gt;

%26lt;TD%26gt;%26lt;INPUT TYPE="TEXT" NAME="zip"%26gt;%26lt;/TD%26gt;

%26lt;/TR%26gt;

%26lt;/TABLE%26gt;

%26lt;INPUT TYPE="BUTTON" VALUE="Download document"

onClick="sendForm(document.testform)"%26gt;

%26lt;/FORM%26gt;

%26lt;/BODY%26gt;

%26lt;/HTML%26gt;


下面再给出需要用到的doc.html文件

doc.html

%26lt;HTML%26gt;

%26lt;BODY%26gt;

%26lt;H3%26gt;This is the document%26lt;/H3%26gt;

%26lt;/BODY%26gt;

%26lt;/HTML%26gt;

为了测试一下这个功能，你可以打开cookie1.html并点击中按钮，你将被带到表单网页。假如你回到cookie1.html文件并点击按钮你就回直接连到文档去。