I am aware that I can use the IF(ISERR.. function to stop the cell display this message, but I can see to get the cell to give a blank display when there is no value in D18,(the formula works OK). Any help will be appreciated.
=IF(ISERR(($C$9*(E18+F18))+($C$10*E18)+C18)/D18,"",(($C$9*(E18+F18))+($C$10*E18)+C18)/D18)
=IF(ISERR(($C$9*(E18+F18))+($C$10*E18)+C18)/D18,"",(($C$9*(E18+F18))+($C$10*E18)+C18)/D18)