Jquery - Access A Dynamically Created Control Through Javascript?

I've a JavaScript function in my page through which i make some elements in the page as 'JQuery UI droppable'.

function setDroppableTargets()
{
$(.cssDockZone).droppable();
}

But the elements with the class cssDockZone is created dynamically upon user interaction. So in the code behind i create the control first and finally at the end i register a scriptblock which calls setDroppableTargets().

//set droppable targets ClientScript.RegisterClientScriptBlock(this.GetType(), "setDroppableTargets", "setDroppableTargets()", true);

But the javascript function is invoked before the controls are created eventhough i register the script at the end (after creating the controls) and i cross checked it by getting the elements with class name '.cssDockZone' and i getting it as 0.

$(.cssDockZone).length