无法使用GET方法显示MySQL数据

Question

经销商信息存储在MySQL数据库中，其中包含以下列：Name, CompanyName, ContactName, emai, password, liststate, listcountry等。

liststate =州 listcountry = Contry

我试图用html选择表单获取经销商数据但由于某种原因它没有显示任何内容。我也找不到任何php错误日志。我有什么遗漏或需要任何改进

<?php
function varscan($str) {
  return ($str != NULL)?ereg_replace('[^0-12]', "", $str):'0';
}

function varscanchar($str) {
  return stripslashes(str_replace(array('+','=','-','*',',',"'",'"','<','>'),array('&#43;','&#61;','&#45;','&#42;','&#44;','&#39;','&quot;','&lt;','&gt;'),$str));
}
$liststate = varscanchar($_GET['liststate']);
//$liststate = $_GET['liststate'];
$listcountry = varscanchar($_GET['listcountry']);
//$listcountry = $_GET['listcountry'];
if($liststate || $listcountry)
{
  echo "<center><h1>Dealers in $liststate</h1></center>";
$db = mysql_connect("localhost", "databaseuser", "dbuserpassword");
    mysql_select_db("databasename");
    if($listcountry=="" || $listcountry=="Country") { $listcountry="none"; }
    else
    {
      $sql = "SELECT * FROM dist WHERE (liststate='".$listcountry."') ORDER BY `city`";
    }
    if($liststate==""|| $liststate=="State/Province") { $liststate="none"; }
    else
    {
      $sql = "SELECT * FROM dist WHERE (state='".$liststate."') ORDER BY `city`";
    }
    //echo $sql;
    $result = mysql_query($sql);
    echo "<form method=\"post\" action=\"$PHP_SELF\">";
    echo '<table border=1 align="center">';
    $sw=true;
    if($result){
    while ($myrow = mysql_fetch_assoc($result))
    {

        if($myrow['map']=="y" || $myrow['map']=="Y")
        {
          if($sw==true)
          {         
            echo '<tr bgcolor="#99CCFF">';
            echo '<td><b><font size="2">Company</font></b></td>';
            echo '<td><b><font size="2">Address</font></b></td>';
            echo '<td><b><font size="2">City</font></b></td>';
            echo '<td><b><font size="2">State</font></b></td>';
            echo '<td><b><font size="2">Zip</font></b></td>';
            echo '<td><b><font size="2">Phone</font></b></td>';
            echo '<td><b><font size="2">Website</font></b></td>';
            echo '<td><b><font size="2">Email</font></b></td>';
            echo '</tr>';
            $sw=false;
          }
          echo "<tr>
          <td><font size=\"2\">$myrow[company]</font></td>
          <td><font size=\"2\">$myrow[address]</font></td>
          <td><font size=\"2\">$myrow[city]</font></td>
          <td><font size=\"2\">$myrow[state]</font></td>
          <td><font size=\"2\">$myrow[zip]</font></td>
          <td><font size=\"2\">$myrow[phone]</font></td>
          <td>".((empty($myrow['website']) || ($myrow['website'] == 'none'))?'':"<a href=\"http://$myrow[website]\"  target\"_blank\"><font size=\"2\">Visit our site</font></a>")."</td>
          <td><a href=\"mailto: $myrow[email]\"><font size=\"2\">Email us</font></a></td>
          </tr>";
          $count=true;
        }
    }
    }
    }
?>