I have a constant sum style question where there are three fields where a respondent must provide a percentage response (between 0-100%). The sum of the responses must be less than or equal to 100. There is no obvious way to do this within the questions options as the Must Total functionality allows only to set to an exact value. I assume this is possible with custom javascript. This is not an area of expertise so before I waste a lot of time trying to figure it out, has anyone else come across this requirement and is able to share a solution or point me in the right direction?