我有一个注册表单，它会动态检查数据库中现有的用户名和电子邮件地址。但是，它似乎不适用于 FireFox 或 IE。不过，它在 Safari 和 Chrome 上很棒。这是代码：
<input type="text" name="username" id="username" placeholder="Username" class="registerinvitel" onKeyUp="resettooltip();" onFocusOut="check_register_exist('username');" autocomplete="off" />
和 JavaScript：
function check_register_exist(meth){
var cueajaxRequest; // The variable that makes Ajax possible!
try{
// Opera 8.0+, Firefox, Safari
cueajaxRequest = new XMLHttpRequest();
} catch (e){
// Internet Explorer Browsers
try{
cueajaxRequest = new ActiveXObject("Msxml2.XMLHTTP");
} catch (e) {
try{
cueajaxRequest = new ActiveXObject("Microsoft.XMLHTTP");
} catch (e){
// Something went wrong
alert("Your browser broke!");
return false;
}
}
}
// Create a function that will receive data sent from the server
cueajaxRequest.onreadystatechange = function(){
if(cueajaxRequest.readyState == 4){
var cuerez = cueajaxRequest.responseText;
if ( cuerez == 'exist' ) { infotooltip(meth, cuerez);
document.getElementById('chk'+meth).value = "exist";
} else { document.getElementById('chk'+meth).value = "ok"; }
}
}
var curchk = document.getElementById(meth).value;
var queryString = "meth="+meth+"&u=" + curchk;
cuenocache = Math.random();
cueajaxRequest.open("GET", "/ajax/check.php?" + queryString + "&nocache=" + cuenocache, true);
cueajaxRequest.send(null);
}
有什么想法可以改变它以使其工作吗？AJAX check.php 代码如下（但我认为这不是问题）：
<?
include "../conf/config.php";
if(isset($_GET['meth'])) { $meth = $_GET['meth']; } else { $meth = ''; }
if(isset($_GET['u'])) { $u = $_GET['u']; } else { $u = ''; }
if ( $meth == 'username' ) {
$query_chkuser = mysql_query("SELECT * FROM members WHERE Username = '$u'");
$query_nr_res = mysql_num_rows($query_chkuser);
if ( $query_nr_res == '1' ) { echo "exist"; } else { echo "ok"; }
}
elseif ( $meth == 'email' ) {
$query_chkuser = mysql_query("SELECT * FROM members WHERE Email = '$u'");
$query_nr_res = mysql_num_rows($query_chkuser);
if ( $query_nr_res == '1' ) { echo "exist"; } else { echo "ok"; }
}
else {}