Rules for writing function:
1. At first function type should be started with the sign (=),
2. Bracket is placed to the right of function and argument to be typed in the bracket.
3. If the arguments are there, these should be separated by the signs of () or colon (;).
4. In the function expression maximum 255 letters can be used.
5. Digits are also considered as argument.
6. In one function maximum 30 arguments can be used.
17. In the text function argument should be kept in quotation sign.
8. To write function capital or small letters can be used.
9. There should not be any gap in between brackets of function and argument.
10. There are some functions, which do not need argument.