def insert_parameter(self, pname, ptype):
        "Inserts a new parameter"
        index = self.insert_id(pname, SharedData.KINDS.PARAMETER, SharedData.KINDS.PARAMETER, ptype)
        #set parameter's attribute to it's ordinal number
        self.table[index].set_attribute("Index", self.shared.function_params)
        #set parameter's type in param_types list of a function
        self.table[self.shared.function_index].param_types.append(ptype)
        return index
Inserts a new parameter