[jQuery] 点击这里搜索...

我们经常看到有些搜索框内有灰色的文字:点击这里进行搜索... 我们点击的时候,他就会自动消失. 使用jQuery可以很方便的实现这个功能.

HTML:

 <form action="#" method="post">
   <input id="SearchText" name="text" />
    <button>Search</button>
 </form>

JavaScript:

 function populateElement(selector, defvalue) {
    if($.trim($(selector).val()) == "") {
         $(selector).val(defvalue);
    }
  
    $(selector).focus(function() {
        if($(selector).val() == defvalue) {
            $(selector).val("");
        }
    });
    
    $(selector).blur(function() {
         if($.trim($(selector).val()) == "") {
            $(selector).val(defvalue);
        }
    });
 }

 
使用方法:

populateElement('#SearchText', 'Enter your search term here..');

just test html code display

<input name ="remember" type="checkbox"> Remember me next time<br> 

--
令狐葱
http://linghucong.blogspot.com
MSN：jiguofei@msn.com

test

Remember me next time


php中图片验证码的生成

/*文件一：authpage.php*/

请输入验证码：

/*文件二：*/

//生成验证码图片
Header("Content-type: image/PNG");
srand((double)microtime()*1000000);//播下一个生成随机数字的种子，以方便下面随机数生成的使用

session_start();//将随机数存入session中
$_SESSION['authnum']="";
$im = imagecreate(62,20); //制定图片背景大小

$black = ImageColorAllocate($im, 0,0,0); //设定三种颜色
$white = ImageColorAllocate($im, 255,255,255);
$gray = ImageColorAllocate($im, 200,200,200);

imagefill($im,0,0,$gray); //采用区域填充法，设定（0,0）

while(($authnum=rand()%100000)<10000);
//将四位整数验证码绘入图片
$_SESSION['authnum']=$authnum;
imagestring($im, 5, 10, 3, $authnum, $black);
// 用 col 颜色将字符串 s 画到 image 所代表的图像的 x，y 座标处（图像的左上角为 0, 0）。
//如果 font 是 1，2，3，4 或 5，则使用内置字体

for($i=0;$i<200;$i++) //加入干扰象素
{
$randcolor = ImageColorallocate($im,rand(0,255),rand(0,255),rand(0,255));
imagesetpixel($im, rand()%70 , rand()%30 , $randcolor);
}
ImagePNG($im);
ImageDestroy($im);
?>

参考文章：http://www.phpe.net/articles/353.shtml
http://www.webdn.com/web_file/program/php/0602080424/

在登陆界面实现Remember me功能

登陆form中有：

 Remember me next time

设置session之后需要设置cookie。cookie就是临时存储用户信息的文件，保存在用户机器上。一下代码位于登陆中验证用户通过后：

   /* Username and password correct, register session variables */
 $user = stripslashes($_POST['user']);
 $_SESSION['username'] = $user;
 $_SESSION['password'] = $pass;

 /**
  * the user has requested that we remember that he's logged in, so
  * we set two cookies. One to hold his username,
  * and one to hold his password. We set them both to
  * expire in 100 days. Now, next time he comes to our site, we will
  * log him in automatically.
  */
 if(isset($_POST['remember'])){
    setcookie("cookname", $_SESSION['username'], time()+60*60*24*100, "/");
    setcookie("cookpass", $_SESSION['password'], time()+60*60*24*100, "/");
 }
检查是否设置cookie：
function checkLogin(){
 /* Check if user has been remembered */
 if(isset($_COOKIE['cookname']) && isset($_COOKIE['cookpass'])){
    $_SESSION['username'] = $_COOKIE['cookname'];
    $_SESSION['password'] = $_COOKIE['cookpass'];
 }

 /* Username and password have been set */
 if(isset($_SESSION['username']) && isset($_SESSION['password'])){
    /* Confirm that username and password are valid */
    if(confirmUser($_SESSION['username'], $_SESSION['password']) != 0){
       /* Variables are incorrect, user not logged in */
       unset($_SESSION['username']);
       unset($_SESSION['password']);
       return false;
    }
    return true;
 }
 /* User not logged in */
 else{
    return false;
 }
}

在logout的时候

if(isset($_COOKIE['cookname']) && isset($_COOKIE['cookpass'])){
 setcookie("cookname", "", time()-60*60*24*100, "/");
 setcookie("cookpass", "", time()-60*60*24*100, "/");
}
参考：http://evolt.org/article/comment/17/60265/index.html