js函数返回值有关问题

function imginfo()
{
    var strtemp="123";
  jq(document).ready(function(){
    jq.post(
      'dt3.php',
      {
        a:1       
      },
      function (data)
      {
        var str=data.split("|");
        for(var i=1; i<=str.length-1;i++){
            var temparr=str[i-1].split("@");
            if(i<str.length-1)
            {
            strtemp += "["+temparr[2]+","+temparr[0]+","+temparr[1]+"]"+",";
             }
            else
            strtemp += "["+temparr[2]+","+temparr[0]+","+temparr[1]+"]";            
        }      
      }
    );
});
  return strtemp;

<?php
require_once './source/class/class_core.php';
require_once './source/function/function_home.php';
$discuz = & discuz_core::instance();
$discuz->init();
//print_r($_G);

//$str="1,1,1,1,1,1";
//DB::query("insert into dz_plugin1 (title,content,datetime,username,uid,filename) values ($str)");



$result=DB::query("select * from dz_plugin2");

$buff2="";
while($rs = mysql_fetch_array($result)){
    
    $buff2.=$rs['title']."@".$rs['url']."@".$rs['filename']."|";
}
echo $buff2;

?>