problem using C# and Action Script3 api

[C# Programming]

hello guys
i using C# and action script 3 .
and write code in action ascript 3
function callingme(itemp:String):String
{
temp=int(itemp);
myDelay.start();
return "";
}
ExternalInterface.addCallback("callingme",callingme);

and i called it in c# The following figure:

string com = "" + temp.ToString() + "";
flash_argham.CallFunction(com);

but I encountered with error The following figure :
Error HRESULT E_FAIL has been returned from a call to a COM component.

note: this code it work in action script 2 but not work in action acript 3.
pleas help me

hamed development