Find Element ID - Expression Expected Error

I'm having issues when trying to run my web app. I'm getting an expression expected error at runtime on the portion of my code that is designed to retain the screen position of multiple drag panels.

Code:
var target = $this).attr("id");

should return the id of the uniquely named panel so it can be used later in code to identify the _DragPanelExtender.BehaviorID

Code:
$find('<%=' + target + '_DragPanelExtender.BehaviorID%>').set_location(new Sys.UI.Point(parseInt(temp[0]), parseInt(temp[1])));

I haven't been able to verify if the dragPanel's id name is being used, it just errors out here. In the following code, I am attempting to preserve the position of multiple dragPanel's after postback?
Code:
function pageLoad() {

//get element id name of button clicked
var target = $(this).attr("id");
// call the savePanelPosition when the panel is moved
$find(target).add_move(savePanelPosition);
var elem = $get("<%=HiddenField1.ClientID%>");

[code]...