Defaulting a field and setting disabled on the form load; changing a text field value based on the other picklist field value.

function feeevent() {

    var feeattrib = Xrm.Page.getAttribute("new_fee");

    var feecontrl = Xrm.Page.getControl("new_fee");

    feeattrib.setValue("$ 400");

    feecontrl.setDisabled(true);

}

function bandevent() {

    var picklistOne = Xrm.Page.getControl("new_chargingband");

    var picklistOneAttribute = picklistOne.getAttribute();

    var picklistOneSelectedOption = picklistOneAttribute.getSelectedOption();

    var picklistOneSelectedText = "";

    var feecontrl = Xrm.Page.getControl("new_fee");

    var feeattrib = Xrm.Page.getAttribute("new_fee");

    if (picklistOneSelectedOption != null) {

        picklistOneSelectedText = picklistOneSelectedOption.text;

    }

    if (picklistOneSelectedText != null && picklistOneSelectedText != "") {

        if (picklistOneSelectedText == "Micro") {

            feecontrl.setDisabled(false);

            feeattrib.setValue("$ 400");

            feecontrl.setDisabled(true);

        }

        if (picklistOneSelectedText == "Small") {

            feecontrl.setDisabled(false);

            feeattrib.setValue("$ 800");

            feecontrl.setDisabled(true);

        }

        if (picklistOneSelectedText == "Medium") {

            feecontrl.setDisabled(false);

            feeattrib.setValue("$ 1600");

            feecontrl.setDisabled(true);

        }

        if (picklistOneSelectedText == "Large") {

            feecontrl.setDisabled(false);

            feeattrib.setValue("$ 2400");

            feecontrl.setDisabled(true);

        }

    }

}