How to prevent more then 1 dialog boxes opening on page at a single time

I am trying to open dialog box but it is opening 2 times.

function postRenderHandler(ctx) {
    var jsViewContainer = $("#WPQ2_ListTitleViewSelectorMenu_Container");
    var jsViewLink = $("#WPQ2_ListTitleViewSelectorMenu_Container_surfaceopt0");

    if (jsViewLink.text() === "Upload Invoices") {
        jsViewContainer.append('<a class="ms-pivotControl-surfacedOpt-selected" id="WPQ2_ListTitleViewSelectorMenu_Container_surfaceoptCustom">Upload Invoices</a>');
        jsViewLink = $("#WPQ2_ListTitleViewSelectorMenu_Container_surfaceoptCustom");
        jsViewLink.siblings().hide();

        jsViewLink.on('click', function () {
            window.location.hash = "";

            if (!window.location.origin) {
                window.location.origin = window.location.protocol + "//" + window.location.hostname + (window.location.port ? ':' + window.location.port : '');
            }

            var options = {
                url: window.location.protocol + "//" + window.location.host + _spPageContextInfo.siteServerRelativeUrl
                    + "/_layouts/FruitFactory.ApplicationPages/UploadInvoices.aspx?URL=" + window.location.origin + window.location.pathname,
                dialogReturnValueCallback: dialogReturnCallback
            }

            SP.UI.ModalDialog.showModalDialog(options);
            return false;
        });
    }
    else {
        jsViewContainer.hide();
    }
}