插件88：输入提示

<?php // Plug-in 88: Input Prompt// This is an executable example with additional code supplied// To obtain just the plug-ins please click on the Download link$value = '';if (isset($_POST['uname'])){   $value = $_POST['uname'];   echo "You submitted the value '$value'<br />";}$self = $_SERVER['PHP_SELF'];echo    "<br /><form method='post' action='$self'>\n";echo    "Username: " . PIPHP_InputPrompt(        "name='uname' type='text' size='50' value='$value'",        'Required Field: Please enter your Username here');echo    "<input type='submit'></form>\n";function PIPHP_InputPrompt($params, $prompt){   // Plug-in 88: Input Prompt   //   // This plug-in returns the HTML and JavaScript required   // to add a prompt to an input field which is only displayed   // when that field has an empty value. It requires these   // arguments:   //   //    $params: Parameters to control the input such as   //             name=, type=, rows=, cols=, name=, size=   //             value=, and so on   //    $prompt: The prompt text to display   $id = 'PIPHP_IP_' . rand(0, 1000000);   $out = <<<_END<input id='$id' $params   onFocus="PIPHP_JS_IP1('$id', '$prompt')"   onBlur="PIPHP_JS_IP2('$id', '$prompt')" />_END;   static $PIPHP_IP_NUM;   if ($PIPHP_IP_NUM++ == 0) $out .= <<<_END<script>PIPHP_JS_IP2('$id', '$prompt')function PIPHP_JS_IP1(id, prompt){   if ($(id).value == prompt) $(id).value = ""}function PIPHP_JS_IP2(id, prompt){   if ($(id).value == "") $(id).value = prompt}function $(id){   return document.getElementById(id)}</script>_END;   return $out;}?>