excel is isna
The Microsoft Excel ISNA function can be used to check for a #N/A (value not available) error. The ISNA function is a built-in function in Excel that is categorized as an Information Function. It can be used as a worksheet function (WS) in Excel. As a worksheet function, the ISNA function can be entered as part of a formula in a cell of a worksheet. The syntax for the ISNA function in Microsoft Excel is: