msg box if blank cell vba code

[sikander1986]

Hi,
I want to know how to know if a cell is blank.

If Column G is “Closed” then column D & E should be blank automatically & Column C should not be blank if column G is closed & column F should be not blank if column G is closed & should be filled with a date in format of (mm/dd/yyyy). If these conditions are not getting met then message box should popup.
IF column C is equal to the values of column J i.e. from J2 to J5 then column B should be Zero automatically. And if the column C value is not equal to the values of J2 to J5 then column B should not be Zero.

Thanks for your help in advance...