Why does IF command and formula break ?

[Partypiepom25]

=IF(C10="01", "No Sub Project", IF(C10="03", "Sub Project 1", IF(C10="04", "Sub Project 2", IF(C10="05","Sub Project 3", IF(C10="06", "Sub Project 4", IF(C10="07", "Sub Project 5", IF(C10="08", "Sub Project 6", IF(C10="09", "Sub Project 7", IF(C10="13", "Sub Project 8", IF(C10="14", "Sub Project 9", IF(C10="15", "Sub Project 10", IF(C10="16", "Sub Project 11", IF(C10="17", "Sub Project 12", IF(C10="18", "Sub Project 13", IF(C10="19", "Sub Project 14", IF(C10="20", "Sub Project 15", IF(C10="27", "AMS-Drainage Strategy",IF(C10="28", "AMS - Buildings", IF(C10="29", "AMS - Roads",IF(C10="30", "AMS – Open Space", IF(C10="35", "AMS- Leisure Community",IF(C10="36", "AMS - TBC", IF(C10="37", "AMS-TBC", IF(C10="38", "AMS - TBC", IF(C10="39", "AMS - TBC", "Refer")))))))))))))))))))))))))

This sits beneath a drop down box .. and forany number higher than 13 it goes to "refer".. Any help as why ?

 

[StephenCrump]

You are checking whether C10 = "01", "03", "04" etc. These are strings, not numbers. If C10 contains 13, this is not the same as "13".

By the way, I suggest you check out the VLOOKUP function, which is a succinct way to replace nested IFs like this one.