Dataset returns no record, how to compare in expression

Hi,

Using SSRS 2008 R2

Dataset1 returns value Fields!Value1.value

Dataset2 returns value Fields!Value2.value

In expression, i do Fields!Value1.value / Fields!Value2.value.

Also, checking for divide by zero condition iif(Fields!Value2.value = 0, then do not divide). Working fine.

But if dataset2 does not return any record what condition should i check for Fields!Value2.value in expression.

I tried using IsNothing and IsMissing but did not work.

Thanks.