Problem with characters ' " \

If I enter (’ " ) into the cell and then reload the page, the backslashes will appear in the cell (’ " \).
How can I prevent that?

Please, is there anyone to help me? Please, try to type ’ " \ into cell (edtxt) and then reload the page. After I reload the page, my cell content changes to ’ " \.
Why the hell connector writes extra backslashes into database? Is this a bug or am I doing something wrong? Thanks in advance.
This is my code:

<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=utf-8" />
    <link rel="stylesheet" type="text/css" href="codebase/dhtmlxgrid.css">
    <link rel="stylesheet" type="text/css" href="codebase/skins/dhtmlxgrid_dhx_skyblue.css">
    <script src="codebase/dhtmlxcommon.js"></script>
    <script src="codebase/dhtmlxgrid.js"></script>
    <script src="codebase/dhtmlxgridcell.js"></script>
    <script src="codebase/dhtmlxdataprocessor.js"></script>
    <script src="codebase/ext/dhtmlxgrid_validation.js"></script>
    <script src="codebase/connector.js"></script>
    <script>
     var mygrid;
     function doInitGrid() {
       mygrid = new dhtmlXGridObject('mygrid_container');
       mygrid.setImagePath("codebase/imgs/");
       mygrid.setHeader("Name,Address,Phone");
       mygrid.setInitWidths("150,150,*");
       mygrid.setColAlign("left,left,left");
       mygrid.setSkin("dhx_skyblue");
       mygrid.setColSorting("str,str,str");
       mygrid.setColTypes("edtxt,edtxt,edtxt");
       mygrid.enableResizing("true,true,true");
       mygrid.enableMultiselect(true);
       mygrid.enableTooltips("false,false,false");
       mygrid.enableValidation(true);
       mygrid.setColValidators("NotEmpty");
       mygrid.init();
       mygrid.load("codebase/data.php");
       myDataProcessor = new dataProcessor("codebase/data.php");
       myDataProcessor.init(mygrid);
    }
    function addRow() {
        var n = (new Date()).valueOf();
        mygrid.addRow(n,["New name","",""],mygrid.getRowsNum());
        setTimeout('mygrid.selectRow(mygrid.getRowsNum()-1)',500);
        setTimeout('mygrid.selectCell(mygrid.getRowsNum()-1,0,true,false,true)',500);
    }
    function removeRow() {
        mygrid.deleteSelectedRows();
    }
    </script>
</head>
<body onload="doInitGrid();">
    <div id="mygrid_container" style="position:relative;width:600px;height:450px;"></div>
    <button onclick="addRow()">Add</button>   <button onclick="removeRow()">Remove</button><br>
</body>
</html>

data.php:

<?php
require_once("grid_connector.php");
$res=mysql_connect('localhost', 'user', 'password');
mysql_select_db("db");
$conn = new GridConnector($res,"MySQL");
$conn->render_table("Buyers","ID","Name,Address,Phone");
?>

Try to disable Magic Quotes in your php