Keeping cells with formulas "empty" until other information inputted

[rod03801]

This is probably a very simple question to all you Excel experts out there! I'm still an amateur, but learning more all the time. I am amazed at the great things we can do with this program!

I am using 2003, on Windows XL

I am creating a VERY simple spreadsheet. It is a spreadsheet to keep track of a group of peoples' weight change (as # of lbs and % change). This will be an ongoing spreadsheet. Updated weekly, I suppose. It only involves 3 or 4 people. So I'm picturing a column with the names. A column with the starting weight. Then the next column would be Week 1. Next column would be "change in lbs", next column would be "% change". Then week 2, "change in lbs", "%change" etc.

Obviously, this can only go so far across, so right below that table, would start another one with the same columns, with obviously progressive week headings.

I'm ok with the actual formulas of course. I am creating this spreadsheet for someone else, so I want them to just have to fill in the new weights each week, with columns beside it that will automatically figure out the weight change, and the % of the change, so I want the formulas already there.

SO, my main question would be, how do i have those cells be empty until the weight is entered each week?

As it is NOW, of course the "change in lbs" column all has zeros, (basically this is a b1-c1 formula) and the % change column has #div/0! (because there is no data yet, and so its telling me I can't divide by zero, LOL) (This formula is a d1/b1 formula)

I'm sure there MUST be a way to have those cells stay blank, UNTIL the new week's weight is entered. Yes?

I'm sorry if this is a totally stupid question! I look forward to any help!

Thank you!

 

[JackDanIce]

Welcome to the board.

Try:

=IF(ISBLANK(C1),"",B1-C1)

And

=IF(ISERROR(D1/B1),"",D1/B1)

 

[rod03801]

Thank you SO much! That was JUST what I needed!

If I should start a separate thread, since it's an unrelated question, let me know, but I'm going to ask here, anyway for now.

As I said, this spreadsheet is for someone else. I have warned him that if he deletes any numbers, it should only be numbers that he himself inputs. That if he deletes something in a cell with a formula, the formula of course is deleted, and would have to be re entered.

Is there a way to "lock" formulas into certain cells, so that they CAN'T be deleted by a user? (While still allowing them to input into appropriate cells)

Probably not, but Excel does so many other amazing things, I figured there's a good chance it can do that too.

 

[JackDanIce]

You can lock specified cells, but you're right, it's totally unrelated to the original thread so suggest posting a new one. Also, you could try using Google to search for "Excel lock cells" e.g. http://support.microsoft.com/kb/214081