Ensure value of multiple commissions fields equals 100%

This script checks to ensure that sales commission amounts equal 100% (1.00) before allowing the project to be saved. It can be modified to support any number of sales rep commissions fields.

Enrich records with additional sales management information.
Easily reusable/extendible with minimal effort.
Might solve this case using allocation grid custom field, but this solution allows user pick lists and retains a more detailed audit trail.

A new custom Commission section has been added to the project form. A user script is triggered as the project saves to validate the commission values entered.

Commission custom section on the project properties form.

Follow the steps below or download the solutions file, see Creating Solutions for details.

Setup

Create a new Project form script deployment.
Enter a Filename and click SAVE. The extension ‘.js’ is automatically appended if not supplied.
Click on the script link to launch the Scripting Studio.
(1) Copy the Program Listing below into the editor, (2) set the Before save event, and set checkCommish as the Entrance Function.
Set up the required number of custom field pairs for Project. The first in each pair is a Pick List with a List source of User. The second in each pair is a Ratio. You can set the Divider text for the first custom field to Commission to place the custom fields in their own section.
Use the Form schema to identify the correct param names for the custom fields and change the array at the top of the script accordingly.

Tip:
If the new custom fields are not listed in the Form schema, go to Projects, open a project form (this with will refresh the custom field list), and then open the Scripting Studio again.

Program Listing

          // ADD YOUR REP AND RATIO CUSTOM FORM FIELD NAMES TO THE ARRAY BELOW
var repCompFlds = [
    'prj_sales_rep_1__c', 'prj_sales_rep_ratio_1__c', // Use Form schema to find param names
    'prj_sales_rep_2__c', 'prj_sales_rep_ratio_2__c'
];

function checkCommish(type) {

    try {
        var _len = repCompFlds.length,
            _i = 1, // Skip over sales rep name
            _j = 0,
            totalComp = 0;

        while (_i < _len) {
            totalComp += parseFloat(NSOA.form.getValue(repCompFlds[_i]));
            _i += 2; // Skip over sales rep name
        }

        var totalCompRound = round(totalComp, 2),
            totalCompPercent = totalCompRound * 100;
        if (totalCompRound !== 0 && totalCompRound != 1) {

            NSOA.form.error(
                '',
                'The total sales commission ' + totalCompRound +
                ' (' + round(totalCompPercent, 2) + '%) must equal 100%!'
            );

            for (_j; _j < _len; _j++) {
                NSOA.form.error(repCompFlds[_j], 'Please check and re-save.');
            }
        }

    } catch (e) {
        NSOA.meta.log('fatal', "Error running the script: " + e);
    }

}

function round(number, decimals) {
    return (Math.round(number * Math.pow(10, 2)) / Math.pow(10, 2)).toFixed(decimals);
}