How to create a function

[FrozenRope]

Thank you in advance for your help. I'm just learning about functions and am
stuck on how to achieve the following "IF/THEN" scenario:

Cell A1: $100
Cell B1: 21%
Cell C1: $200

Cell D1 will contain the formula:

I need a function where the value found in A1 ($100) will be displayed IF B1
is larger than 30%. If it's not larger, display the value in C1 ($200).

Also, how would this change if the 30% is a value that I want to globally
change (I've created a defined name of "Value_Percentage")

Thanks for the shove in the right direction. Much appreciated!

 

[John C]

=IF(B1>value_percentage,A1,C1)

 

[FrozenRope]

Worked like a charm John. Thank you VERY much.

=IF(B1>value_percentage,A1,C1)