I have script like this
 function getval(sel) {
         var id= sel.value;  
                $.ajax({
                        type:"POST",
                        url:"./tab.php",
                        data:{id:id,task:'search'},
                         success: function(response){
                             //(I don't know what i should write for pass to php code)
                         }
            });
    }
I don't know how I can pass data response to php code ?
For Example: if I alert response, it's show 123 .so I want pass value 123 to a variable in php 
$id = 123 
 
     
     
     
    