>>>What is a recommended method of comparing to NULL? I need to determine if a value of a field has changed. But when it changes to NULL value (and it is allow for this field) the comparison to NULL is NULL. Any suggestions on how to deal with this?
>>>
>>>Thank you.
>>
>>IF ISNULL(YourField)
>
>Yes, I know this function. What I was asking is how to compare current value with old value. This is the segment of code I was using:
>
>

>!(EVALUATE(FIELD(i)) == OLDVAL(FIELD(i), "V_MYTABLE"))
>

>
>What I ended up doing is checking if value before change was NULL and after change is NULL and use the result. As the following:
>
>

>IF (!ISNULL(EVALUATE(FIELD(i))) AND ISNULL(OLDVAL(FIELD
>(i), "V_V_MYTABLE"))) OR ;
>(ISNULL(EVALUATE(FIELD(i))) AND !ISNULL(OLDVAL(FIELD
>(i), "V_V_MYTABLE"))) OR ;
>!(EVALUATE(FIELD(i)) == OLDVAL(FIELD(i), "V_V_MYTABLE"))
>

>
>Thank you very much for your help.

See Re: Last Updated User Thread #988451 Message #988671 (FieldChanged function).

But actually, you may try

IF NVL(evaluate(field(i)),'Some Value that never occurs') = nvl(oldval(Field(i)),'Some Value that never occurs')

*Value has not changed
endif