Use this function to see if the contents of a field match a given value. If the contents differ from the given value, an error message displays.
Refers to the current field.
The value that you want to compare with the contents of the field referred to by
fieldref. The data type of Value must match the type of the field.
If you include Value and the contents of the field do not match, an error message is displayed.
If you omit Value and the content of the field is zero or blank (empty string), an error message is displayed.
This function is similar to thefunction.