Dynamics CRM 2011: javascript, 'null' is null not an object. error

Question

I am using JavaScript on Dynamics CRM 2011. I am trying to create a new field by comparing two date fields. however, I think something is wrong with null value. cas error message shows up: 'null' is null not an object.

The following is the script. Please have a look, and let me know what you think.

function m1status() {

    var m1date = Xrm.Page.getAttribute("new_m1date").getValue()

    var today = Xrm.Page.getAttribute("new_todayis").getValue()

    if (m1date == null) {

        Xrm.Page.getAttribute("new_m1status").setValue('Not Booked');}

    else if (m1date.getTime() >= today.getTime()) {

        Xrm.Page.getAttribute("new_m1status").setValue('Booked');}

    else {

        Xrm.Page.getAttribute("new_m1status").setValue('Completed');}

    //Set the Submit Mode
    Xrm.Page.getAttribute("new_m1status").setSubmitMode("always");

}

Also most likely the default value is null. cas nothing is shown up.

Thanks so much.

Answer 1

There are some typos in your code, however you can rewrite your code in this way and fill the missing actions.

function m1status() {

    var m1date = Xrm.Page.getAttribute("new_m1date").getValue();
    var today = Xrm.Page.getAttribute("new_todayis").getValue();

    // you can have 4 cases
    // 1: both fields are null
    if (m1date == null && today == null) {
        Xrm.Page.getAttribute("new_m1status").setValue('Not Booked');
    }
    // 2: both fields are not null
    if (m1date != null && today != null) {

        if (m1date.getTime() >= today.getTime()) {
            Xrm.Page.getAttribute("new_m1status").setValue('Booked');
        }
        else {
            Xrm.Page.getAttribute("new_m1status").setValue('Completed');
        }
    }
    // 3: first field is not null, second field is null
    if (m1date != null && today == null) {
        // what need to do in this case?
    }
    // 4: first field is null, second field is not null
    if (m1date == null && today != null) {
        // what need to do in this case?
    }

    Xrm.Page.getAttribute("new_m1status").setSubmitMode("always");
}