Validate Help - First Scripts

Apologies if this is elementary, this is my first set of scripts.  Any input would be appreciated.  Please ignore why my Company wants to take this route but here goes. 

I've created a script to set line items when an Opportunity record is created.  This seems to work as designed. 
function clientPageInit(type){

        for (var i = 0; i < 3; i++){

            // selects the item sublist
            nlapiSelectNewLineItem('item');

            switch(i) {
                case 0:
                    nlapiSetCurrentLineItemValue('item', 'item', 1712, true, true);
                    break;
                case 1:
                    nlapiSetCurrentLineItemValue('item', 'item', 1713, true, true);
                    break;
                case 2:
                    nlapiSetCurrentLineItemValue('item', 'item', 1714, true, true);
                    break;
            }

            // set the item, price level and amount values on the currently selected line