The formula you typed contains an error. Try one of the following: Make sure you've included all parentheses and required ...

The formula you typed contains an error. Try one of the following: 

• Make sure you've included all parentheses and required arguments.
• To get assistance with using a function, click Insert Function on the Formulas tab (in the Function Library group).
• If you include a reference to another sheet or workbook, verify that the reference is correct.
• If you are not trying to enter a formula, avoid using an equal sign (=) or minus sign (-), or precede it with a single quotation mark ( ' ).
• For more information about common formula problems, click Help.