# Operator '<operatorname>' is not defined for types '<typename1>' and '<typename2>'

Visual Studio 2005

#### Error Message

Operator '<operatorname>' is not defined for types '<typename1>' and '<typename2>'. Use 'Is' operator to compare two reference types.

An attempt was made to use an operator in a way that is inappropriate for the specified types. This error can be caused by using the "=" operator instead of using the Is operator to compare two objects.

Error ID: BC31080

### To correct this error

1. Use Is operator to compare two reference types.

2. Use the Not operator in conjunction with the Is operator to denote inequality. For example:

```If Not A Is B Then

```