Update Form Problem

I'm having a problem in update form, when I click on the update botton, I'm redirected to a white page and not happen anything more.

<div id="sign_up_form">
      <fieldset>
      <legend class="cad_title"><strong>Cadastro</strong></legend>
      <form  name="cadastro" method="post" action="edit_account_2.php" onsubmit="return formValidation(); return false;">
  <table width="625" border="0">
  <tr>
      <td width="69" style="font-family:vijaya; font-size:20px;">Username:</td>
      <td width="546"><input name="username" type="text" id="nome" size="70" maxlength="60" value=""/>
        <span>*</span></td>
    </tr>
    <tr>
      <td width="69" style="font-family:vijaya; font-size:20px;">Nome:</td>
      <td width="546"><input name="nome" type="text" id="nome" size="70" maxlength="60" value=""/>
        <span>*</span></td>
    </tr>
    <tr>
      <td width="69" style="font-family:vijaya; font-size:20px;">Sobrenome:</td>
      <td width="546"><input name="sobrenome" type="text" id="sobrenome" size="70" maxlength="60"/>
    </tr>
    <tr>
      <td style="font-family:vijaya; font-size:20px;">Sexo:</td>
      <td><input name="sexo" type="radio" value="Masculino" checked="checked" />
        Masculino 
        <input name="sexo" type="radio" value="Feminino" />
        Feminino <span>*</span> </td>
    </tr>
    <tr>
      <td style="font-family:vijaya; font-size:20px;">DDD:</td>
      <td><input name="ddd1" type="text" id="ddd1" size="4" maxlength="2" />
      <span style="font-family:vijaya; font-size:20px; color:#000;">Telefone:</span>
        <input name="telefone" type="text" id="telefone" />
        <span style="color:#000;"><strong>Apenas números</strong></span> </td>
    </tr>
    <tr>
      <td style="font-family:vijaya; font-size:20px;">DDD:</td>
      <td><input name="ddd2" type="text" id="ddd2" size="4" maxlength="2" />
      <span style="font-family:vijaya; font-size:20px; color:#000;">Celular:</span>
        <input name="celular" type="text" id="celular" />
        <span style="color:#000;"><strong>Apenas números</strong></span> </td>
    </tr>
    <tr>
      <td style="font-family:vijaya; font-size:20px;">Cidade:</td>
      <td><input name="cidade" type="text" id="cidade" maxlength="20" />
        <span">*</span></td>
    </tr>
    <tr>
      <td style="font-family:vijaya; font-size:20px;">Estado:</td>
      <td><select name="estado" id="estado">
        <option style="font-family:vijaya; font-size:20px;">Selecione...</option>
        <option value="AC">AC</option>
        <option value="AL">AL</option>
        <option value="AP">AP</option>
        <option value="AM">AM</option>
        <option value="BA">BA</option>
        <option value="CE">CE</option>
        <option value="ES">ES</option>
        <option value="DF">DF</option>
        <option value="MA">MA</option>
        <option value="MT">MT</option>
        <option value="MS">MS</option>
        <option value="MG">MG</option>
        <option value="PA">PA</option>
        <option value="PB">PB</option>
        <option value="PR">PR</option>
        <option value="PE">PE</option>
        <option value="PI">PI</option>
        <option value="RJ">RJ</option>
        <option value="RN">RN</option>
        <option value="RS">RS</option>
        <option value="RO">RO</option>
        <option value="RR">RR</option>
        <option value="SC">SC</option>
        <option value="SP">SP</option>
        <option value="SE">SE</option>
        <option value="TO">TO</option>
          </select>
        <span>*</span></td>
    </tr>
      <td style="font-family:vijaya; font-size:20px;">Pa&iacute;s:</td>
      <td><input name="pais" type="text" id="pais" maxlength="20" />
        <span>*</span></td>
    </tr>
      <td colspan="2"><p>
        <input name="Cadastrar" type="submit" id="cadastrar" value="Atualizar" /> 
        <div class="clear">
          <input name="Limpar" type="reset" id="limpar" value="Limpar" />
        </div>
        <div class="termos_msg">
          <span style="color:#000;"><strong><span>*</a></span>Campos com <span>*</span> s&atilde;o obrigat&oacute;rios!</strong></span></p>
        </div>
      </td>
    </tr>
  </table>
</form>
</fieldset>
</div>

HTML:

<? 
$user="root";
$password="123";
$database="personal_outdoor_2";
$con = mysql_connect(localhost,$user,$password);

if (!$con)
  {
  die('Could not connect: ' . mysql_error());
  }

$username=$_POST['username'];
$nome=$_POST['nome']; 
$sobrenome=$_POST['sobrenome'];
$sexo=$_POST['sexo']; 
$ddd1=$_POST['ddd1']; 
$telefone=$_POST['telefone']; 
$ddd2=$_POST['ddd2']; 
$celular=$_POST['celular']; 
$cidade=$_POST['cidade']; 
$estado=$_POST['estado']; 
$pais=$_POST['pais']; 

mysql_select_db($database, $con);

$query="UPDATE users SET nome='$nome', sobrenome='$sobrenome', sexo='$sexo', ddd1='$ddd1', telefone='$telefone', ddd2='$ddd2', celular='$celular', cidade='$cidade', estado='$estado', pais='$pais' WHERE username='$username'";
mysql_query($query);
echo "Record Updated";
mysql_close();
?>

PHP:

 

Problem Solved, the problem was in database connection.

 

2 hints

1: don't use the mysql functions. check php.net it is discouraged to use them
2: validate all user submitted data. your query is open for SQL Injection attacks if you don't do it.

 

Thanks for the hints.