Dynamic filters in Saved search

var soLines = salesOrder.lineItems;
var filteredIDs = [];

for (var i = 0; i < soLines.length; i++) {
    filteredIDs.push(['customid', 'is', soLines[i].customID])
    filteredIDs.push('OR');
}
filteredIDs.pop();

var mySearch = search.create({
    type: search.Type.SALES_ORDER
    join: 'item',
    columns: [
        "internalid",
        "item.itemid",
        "customid"
    ],
    filters: [filteredIDs]
});