<div class="modal fade" id="myModal2" tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true">
    <div class="modal-dialog">
     <div class="modal-content">
      <div class="modal-header">
       <button type="button" class="close" data-dismiss="modal" aria-hidden="true">×</button>
       <h4 class="modal-title" id="myModalLabel">修改</h4>
      </div>
      <div class="modal-body">
       <?php
           $sql="select * from qxcg ";
           $arr=$db->Query($sql);
           foreach($arr as $v)
           {


           $sqn = "select qxmc from qxypmx where qxdh='{$v[1]}'";
           $att = $db->Query($sqn);

           $squ = "select uid from login where num='{$v[4]}'";
           $ann = $db->Query($squ);
           }
           ?>
           器械名称： <input type="text" value="<?php echo $att[0][0]; ?>" id="rmc"/><br/><br>
            采购数量：<input type="text" value="<?php echo $v[2]; ?>" id="rsl"/><br/><br/>
            采购日期：<input type="text" value="<?php echo $v[3]; ?>" id="rqi"/><br/><br/>
            采购员：<input type="text" readonly="readonly" value="<?php echo $ann[0][0]; ?>" id="rcg"/>


      </div>

      <div class="modal-footer">
       <button type="button" class="btn btn-default" data-dismiss="modal">关闭</button>
       <button type="button" class="btn btn-primary" id="rcbtn">保存</button>
      </div>
     </div><!-- /.modal-content -->
    </div><!-- /.modal -->
   </div>
  </div>

<input type='button' class='xiugai' value='修改' 
  data-toggle='modal' data-target='#myModal2' ids0='{$v[0]}' ids1='{$att[0][0]}'
   ids2='{$v[2]}' ids3='{$v[3]}' ids4='{$ann[0][0]}'/> //这里面的值是通过php代码求出来的，这里就不多说了

function xiugai()
 {
  var ids = ""; //首先定义为空
  var rmc1= "";
  var rsl1= "";
  var rqi1= "";
  var rcg1= "";
  $(".xiugai").click(function() { //给修改按钮一个点击事件
   ids = $(this).attr("ids0");
   rmc1= $(this).attr("ids1"); //把之前有的值取出来，赋值给表单的val
   rsl1= $(this).attr("ids2");
   rqi1= $(this).attr("ids3");
   rcg1= $(this).attr("ids4");
   $("#rmc").val(rmc1);
   $("#rsl").val(rsl1);
   $("#rqi").val(rqi1);
   $("#rcg").val(rcg1);
   $("#rcbtn").click(function(){
    var rmc=$("#rmc").val();
    var rsl=$("#rsl").val();
    var rqi=$("#rqi").val();
    var rcg=$("#rcg").val();

    $.ajax({
     url:"xiugai.php",
     data:{ids:ids,rmc:rmc,rsl:rsl,rqi:rqi},
     type:"POST",
     dataType:"TEXT",
     success:function(xx){
      //alert(xx);
      if(xx.trim()=="OK")
      {
       alert("修改成功");
       Load();
      }
     }
    })
    $('#myModal2').modal('hide')
   })
  });
 }

<?php
$ids=$_POST["ids"];
$rmc=$_POST["rmc"];
$cgsl=$_POST["rsl"];
$cgrq=$_POST["rqi"];
include("DBDA.class.php");
$db=new DBDA();
$sql1="select qxdh from qxypmx where qxmc='{$rmc}'";
$arr=$db->Query($sql1);
$sql="update qxcg set qxdh='{$arr[0][0]}',cgsl='{$cgsl}',cgrq='{$cgrq}' where ids='{$ids}'";
if($db->Query($sql,0))
{
 echo"OK";
}
else
{
 echo"NO";
}