The Excel AND function tests a number of userdefined conditions and returns a result of:
  TRUE if ALL of the conditions evaluate to TRUE 
or  
  FALSE otherwise (i.e. if ANY of the conditions evaluate to FALSE) 
The syntax of the function is :
where the arguments, logical_test1, [logical_test2], etc, are conditions that evaluate to either TRUE or FALSE.
In Excel 2007 or 2010, you can enter up to 255 logical_test arguments to the Excel And function. However, in Excel 2003, the function can only handle up to 30 arguments.
Note that, if the logical_tests evaluate to numbers, instead of logical values, the value zero evaluates to FALSE and all nonzero values are treated as the logical value TRUE.
The following spreadsheet shows three examples of the Excel And function, with different conditions.
Formulas:

Results:

Note that, in the above example spreadsheet:
Further examples of the Excel And function can be found on the Microsoft Office website.
If you get an error from the Excel And Function, this is likely to be the #VALUE! error:
#VALUE!    Occurs if any of the supplied logical_test arguments are text values 