Method Call

Hi all,
    We have a session values in a cache method and need to get those values in a client method (JavaScript).
   
Eg : 
    ClassMethod Method1()
{
    Set %session.Data("Param1")="Data 1"
}

ClientMethod onloadHandler [Language = javascript]
{
   var ret = zenPage.getSessionValues();
}

ClassMethod getSessionValues() As %String [zenMethod]
{
   Set Data = $G(%session.Data("Param1"))
   Quit Data
}

This is the code we implemented. But the problem is getSessionValues() method isn't called.
We need to know how to call a class method from client method.

Thanks,
Syed M