function formCheck(formobj) {
    // name of mandatory fields
    var fieldRequired = Array("first_name", "last_name", "email", "company", "phone");
    // field description to appear in the dialog box
    var fieldDescription = Array("First Name", "Last Name", "Email", "Company", "Phone");
    // dialog message
    var alertMsg = "Please complete the following fields:\n";

    var l_Msg = alertMsg.length;

    for (var i = 0; i < fieldRequired.length; i++) {
        var obj = document.getElementById[fieldRequired[i]];
        if (obj) {
            if (obj.type == null) {
                var blnchecked = false;
                for (var j = 0; j < obj.length; j++) {
                    if (obj[j].checked) {
                        blnchecked = true;
                    }
                }
                if (!blnchecked) {
                    alertMsg += " - " + fieldDescription[i] + "\n";
                }
                continue;
            }
            switch (obj.type) {
                case "select-one":
                    if (obj.selectedIndex == -1 || obj.options[obj.selectedIndex].text == "") {
                        alertMsg += " - " + fieldDescription[i] + "\n";
                    }
                    break;
                case "select-multiple":
                    if (obj.selectedIndex == -1) {
                        alertMsg += " - " + fieldDescription[i] + "\n";
                    }
                    break;
                case "text":
                case "textarea":
                    if (obj.value == "" || obj.value == null) {
                        alertMsg += " - " + fieldDescription[i] + "\n";
                    }
                    break;
                default:
            }
        }
    }
    if (alertMsg.length == l_Msg) {
        return true;
    } else {
        alert(alertMsg);
        return false;
    }
}