layout panel refresh parametr

[ems2811]

Hello.
When calling a function

Code:

$('#lay').layout('panel','center').panel('refresh','./Scripts/get_something.php');

always applied incremental option _
GET request looks like this

Code:

http://localhost/Scripts/get_something.php?_=1429796025673
http://localhost/Scripts/get_something.php?_=1429796025674
http://localhost/Scripts/get_something.php?_=1429796025675

What is this parameter and how to turn it off?