* @throws NoSuchFieldException the the variable cannot be found
*/
protected Object lookupVariable(String variableName) throws NoSuchFieldException
{
NametableStack ntStack = getCurrentContext().getNametableStack();
if (!ntStack.containsName(variableName))
{
throw new NoSuchFieldException("Variable/Function " + variableName + " is not declared before");
}
Object v = ntStack.access(variableName);
if (_logger.isLoggable(Level.FINEST))