Ajax plus PHP for three-level linkage

JS Code

<script type= "Text/javascript" >
function Get_next (t,pid) {//ID of current element, value of current option, usually ID? Anyway, mine is.
$.ajax ({
Type: "POST",
URL: "/index.php?type=company&m=action&a=getnext",
Data: "Pid=" +pid,
DataType: ' JSON ',
Success:function (msg) {
$ ("#" +t). Next (' SELECT '). HTML (MSG.STR);//Stitching HTML
}
});
}
</script>

PHP code

Public Function GetNext ()
{

$next = $sql//Lookup database Pid=post The ID of the SQL
$str = "<option value=" > Please select </option> ";
foreach ($next as $val) {
$str. = "<option value=". $val [' id ']. "' > ". $val [" name "]." </option> ";
}
$msg ["str"] = $STR;
echo Json_encode ($msg);
Die ();
}

Can be called anywhere, but there is a small flaw that I choose to ignore. Hee Hee

Ajax plus PHP for three-level linkage