How to display warning message on the basis of Performance rating on Performance Document??

Summary:

We have added multiple goals and each goal has multiple measurement. Sum of the calculated value of measurement would be the rating of employee. Now we have a requirement that sum of those measurements should not exceed 100. If it is more than 100 than warning message should be displayed.

Content (please ensure you mask any confidential information):

Version (include the version you are using, if applicable):

Code Snippet (add any code snippets that support your topic, if applicable):