jQuery Grid Plugin - jqGrid

Hello, I have the same case, but thought I knew the reason. Please view this script, in the last line I call the function 'header', then the dialog “Delete” doesn't close. But after I removed the line and everything stayed the same. Then, that can I do? Thank you so much.

<?php
  require_once('mysqlsupport.php');
  require_once('connectionvars.php');

  if($_POST[oper] != 'del')
    return;

  $conx = new MySQLConnect($hostname, $username, $password);
  $sql = 'DELETE FROM Afiliados WHERE CodigoInt = ' . $_POST[id];
  $fp = fopen(”../logs/logfilefordelete.txt”, “w”);
  if(fwrite($fp, $sql) == false){
    echo “No se pudo crear el log…<br /><br />”;
  }
  fclose($fp);
  $rs=$conx->createResultSet($sql, $databasename);
  $conx->close();

  header('location:../mainscript.php?rowdeleted=1');
?>

This is a piece of code which defines the value of the parameters for the navigator:

…

    }).navGrid(
      '#pagerAfiliados',
      {edit:false,add:false,del:true},
      {}, // prmEdit (Edit Options)
      {}, // prmAdd (Add Options)
      {url:'scripts/scriptfordelete.php',closeAfterDelete:true,reloadAftersubmit:true}, // prmDel (Del Options)
      {}, // prmSearch (Search Options)
      {}  // prmView (View Options)
    );
…