在同一个页面中,js传值给php


<script type="text/javascript">
            function seltime(){
                var btime=document.getElementById("beginTime").value+document.getElementById("bt").value;
                var etime=document.getElementById("endTime").value+document.getElementById("et").value;                document.location.href="Back.php?beginTime="+btime+"&endTime="+etime+"&subject=9900";
                document.form1.target="left";
                document.form1.submit();
            }
        </script>
        <title>Tree</title>
    </head>
    <body>
        <form id="form1" name="form1" method="get" action="">
         <div align="left" style="width: 190px; height:80px; margin-left:30px; margin-top:6px;">
            <?php echo iconv("utf-8","gb2312","开始时间:");?><input type="text" id="beginTime" name="beginTime" style="width:40px;"/><?php echo iconv("utf-8","gb2312","年");?><select id="bt" name="bt">
             <option selected="selected" value="01">01</option>
             <option value="02">02</option>
             <option value="03">03</option>
             <option value="04">04</option>
             <option value="05">05</option>
             <option value="06">06</option>
             <option value="07">07</option>
             <option value="08">08</option>
             <option value="09">09</option>
             <option value="10">10</option>
             <option value="11">11</option>
             <option value="12">12</option>
     </select><?php echo iconv("utf-8","gb2312","月");?>           <br/>
            <?php echo iconv("utf-8","gb2312","结束时间:");?><input type="text" id="endTime" name="endTime" style="width:40px;"/><?php echo iconv("utf-8","gb2312","年");?><select id="et" name="et">
             <option selected="selected" value="01">01</option>
             <option value="02">02</option>
             <option value="03">03</option>
             <option value="04">04</option>
             <option value="05">05</option>
             <option value="06">06</option>
             <option value="07">07</option>
             <option value="08">08</option>
             <option value="09">09</option>
             <option value="10">10</option>
             <option value="11">11</option>
             <option value="12">12</option>
     </select><?php echo iconv("utf-8","gb2312","月");?>
            <br/>
            <br/>
            <input type="button" id="check" name="check" value="<?php echo iconv("utf-8","gb2312","查询");?>" style="background-color:#CFF; margin-left:30px; border:none;" onclick="javascript:seltime();" />
     </div>
        <hr style="color:Gray; size:1px;"/>
        <div>
        <ul id="navigation">
            <li>
                <?php
                    include("SelectMapDB.php");                    //获取参数
                    $begintime=$_GET["beginTime"];
                    $endtime=$_GET["endTime"];
                ?>
                <img src="image/fold.gif" border="0" align="left"/>
                <a href="Back.php?beginTime=<?php echo $begintime; ?>&endTime=<?php echo $endtime; ?>&subject=9900" target="right"><?php echo iconv("utf-8","gb2312","总行");?></a>怎样将js取得的值，赋给同一页面中的php变量，并同时跳转到下一个页面?
请高人帮忙！