Retain Select Box selection even after the form is submitted in php

Question

I have a page which contains a select box which is used to select a particular user. I also have two radiobuttons for selecting date range. This page is for generating user reports based on the selections. At present when I select the user and preferred date ranges and clicks on submit button reports are generated properly but my selection in select box will be reset to default after submitting.Here My select box is populated from mysql table.

My task is to retain the select box value even after form submit. I have tired so many ways but nothing worked. Can anyone please help me out with this..

Here is my code:

HTML

<div class="box-container-toggle">
                <form class="form-horizontal" name="reportform" id="reportform" action="<?php echo $_SERVER['PHP_SELF'];?>" method="POST" >
                    <div class="box-content">

                            <fieldset>
                            <legend>Developer Reports</legend>

                            <div class="control-group">
                              <label class="control-label" for="select01">Select Developer</label>
                              <div class="controls">
                              <select id="select01" class="chzn-select" name="selectdev" onChange="getapp(this.value)">
                              <option value="">Select developer</option>
                              <?php

                              $qry="select user_id from tab_user_login where type='Developer' and status='approved'";
                              $res=mysql_query($qry);
                              while($row=mysql_fetch_array($res))
                              {
                                  $devid=$row[0];
                                  $qry1="select name from tab_user where user_id='$devid'";
                                  $res1=mysql_query($qry1);
                                  while($row1=mysql_fetch_array($res1))
                                  {
                              ?>
                                  <option value="<?php echo $devid;?>" <?php if($dev!="") { if($dev==$devid) {echo 'selected'; } } ?> ><?php echo $row1[0];?></option>
                                <?php
                                }
                                }
                                ?>
                                </select>
                              </div>
                            </div>



                            <h3> Select Date Range </h3>

                            <div class="control-group">
                            <div class="controls">
                            <label>
                            <input type="radio" name="selectdateradio" value="selectdaterange" onChange="enableblock()"> Select a Date Range
                            <div class="control-group"  id="daterange" style="display:none">
                              <label class="control-label" for="select01">Select Date</label>
                              <div class="controls">
                                <select id="select01" name="selectdate" id="selectdate" onChange="getYesterdaysDate(this.value)">
                                  <option value="Today" >Today</option>
                                  <option value="Yesterday" >Yesterday</option>
                                  <option value="Last 7 Days" >Last 7 Days</option>
                                  <option value="Last 30 Days" >Last 30 Days</option>
                                   <option value="This Week" >This Week</option>
                                  <option value="This Month" >This Month</option>
                                  <!--<option value="Last 6 Months" >Last 6 Months</option>-->
                                </select>
                                <input type="hidden" name="hiddendate" value="" > 
                                <input type="hidden" name="hiddennext" value="" >
                              </div>
                            </div>
                            </label>

                            <label>
                            <input type="radio" name="selectdateradio" value="selectcustomdate" onChange="enablecustomblock()"> Select Custom Date
                            <div class="control-group" id="customdaterange" style="display:none">
                            <div class="control-group">
                                <label class="control-label" for="date01">Start input</label>
                                <div class="input-append date datepicker" data-date="2012-02-12" data-date-format="yyyy-mm-dd">
                              <input name="start_date" id="start_date" type="text"/><span class="add-on "><i class="icon-calendar"></i></span>
                            </div> 
                                <!--<div class="controls">
                                    <input type="text" class="input-xlarge datepicker" name="start_date" id="start_date" onChange="show()"/>
                                </div>-->
                            </div>

                            <div class="control-group">
                                <label class="control-label" for="date01">End Date</label>
                                    <div class="input-append date datepicker" data-date="2012-02-12" data-date-format="yyyy-mm-dd">
                              <input name="end_date" id="start_date" type="text"/><span class="add-on "><i class="icon-calendar"></i></span>
                            </div>
                            <!--    <div class="controls">
                                    <input type="text" class="input-xlarge datepicker" name="end_date" id="end_date" onChange="show()"/>
                                </div> -->

                            </div>
                            </div>
                            </label>

                            </div>
                            </div>
                            <div class="form-actions">
                              <input type="submit" class="btn btn-primary" name="submit" value="Run Reports" >
                              <button type="reset" class="btn">Reset</button>
                            </div>
                            </fieldset>
                    </div>
                    </form>
                    <?php
                        if(isset($_POST['submit']))
                        {
                        $dev=$_POST['selectdev'];
                        $qryy1="select name from tab_user where user_id='$dev'";
                        $ress1=mysql_query($qryy1);
                        $roww1=mysql_fetch_array($ress1);
                        $devname=$roww1[0];
                        $selected=$_POST['selectdateradio'];
                        $customstart=$_POST['start_date'];
                        $customend=$_POST['end_date'];
                        $postdate=$_POST['selectdate'];
                        $hide=$_POST['hiddendate'];
                        $hidden=date("Y-m-d", strtotime($hide));
                        $hide1=$_POST['hiddennext'];
                        $hidden1=date("Y-m-d", strtotime($hide1));
                        date_default_timezone_set("Asia/Kolkata");
                        $today=date('Y-m-d');
                        /*$click=0;
                        $imp=0;
                        $install=0;
                        $rev=00.00;
                        $active=0;*/    
                        }
                        else
                        {

                        }
                        if($_POST['selectdev']=='')
                        $devname='All Developer';
                        if($_POST['selectdate']=='')
                        $postdate="";

                    ?>
                </div>

Answer 1

You must set posted variable before generate the select elements. then you can check the current developer

please try this code before generate select element (for example above the <div class="box-container-toggle"> ) :

<?php 
if(isset($_POST['selectdev']) && $_POST['selectdev']!='') {
    $selectdev = $_POST['selectdev'];
}
?>

Then Use your checking condition as below

<select id="select01" class="chzn-select" name="selectdev" onChange="getapp(this.value)">
                              <option value="">Select developer</option>
                              <?php

                              $qry="select user_id from tab_user_login where type='Developer' and status='approved'";
                              $res=mysql_query($qry);
                              while($row=mysql_fetch_array($res))
                              {
                                  $devid=$row[0];
                                  $qry1="select name from tab_user where user_id='$devid'";
                                  $res1=mysql_query($qry1);
                                  while($row1=mysql_fetch_array($res1))
                                  {
                              ?>
                                  <option value="<?php echo $devid;?>" <?php if(isset($selectdev) && $selectdev==$devid) echo 'selected="selected"'; ?>  ><?php echo $row1[0];?></option>
                                <?php
                                }
                                }
                                ?>
                                </select>