jQuery Grid Plugin - jqGrid

Hello. Can someone help me? I want to delete, add and edit from the grid at the same time some rows, i.e. what are marked with the help of checkboxes. I assume that it is necessary to use multiselect.

But how I can receive parameters of the selected rows, after submiting in the edit/delete form when a post request is sent for the server? Is necessary something like this:

$massiv = $_POST["json"]; 
$decmassiv = json_decode($massiv, true); 
$count = count($decmassiv);

    for ($x=0; $x < $count; $x++){ 
$new = $decmassiv ;  
$id = $new ['id']; 
$name = $new ['name'];  
$email = $new['email'];  
} 
mysql_query("UPDATE user SET name = ".$name.", email = ".$email." WHERE id = ".$id);