window.onload = initForms;

function initForms() {
    for (var i=0; i < document.forms.length; i++) {
        document.forms[i].onsubmit = function() { return validForm(); }
    }
}

function validForm() {

    var allGood = true;
    var ProdName = document.getElementById("ProdName").value;
    var ProdNum = document.getElementById("ProdNum").value;
    var PurchDate = document.getElementById("PurchDate").value;
    var NumLic = document.getElementById("NumLic").value;
    var Dept = document.getElementById("Dept").value;
    var PONum = document.getElementById("PONum").value;
    var inName = document.getElementById("inName").value;
    var inEmail = document.getElementById("inEmail").value;

    if ((ProdName == "") || (ProdNum == "") || (PurchDate == "") || (NumLic == "") ||
        (Dept == "") || (PONum == "") || (inName == "") || (inEmail == "")) {
        alert("Please complete all required fields");
        allGood = false;
    }
    return allGood;
}