=IF(D4=" "," ",SUMIF(Sheet2!C4:C7,D4,Sheet2!D4:D7))...

'SUMIF' is used to copy the value if the value in sheet2 is a number...but if the value in sheet2 is a character...what is the command that i need to used? because if i still used 'SUMIF' it will return #value...can u help me? thank u..

you've got several functions to help you. Check the help on how to use ISTEXT, ISNONTEXT, ISNUMBER. There's also a useful TYPE function which tells you what kind of content exists in the cell

you probably will want to use this with one or more IF functions, and probably in conjunction with the logical functions AND, OR, NOT