如何将对话框设置为前面

Question

大家好我尝试进行对话但是当我尝试显示时，对话框就像这样the dialog stay on back of background

如何将对话框设置为前面？  但是当对话框已经设置在前面时，我希望背景仍然消失或者像那样

这个代码

    <p:remoteCommand name="processBack"
                    action="/prpk_paperless/prpk_new.xhtml?faces-redirect=true">
                </p:remoteCommand>
                <p:remoteCommand name="processSubmit"
                    action="#{pRPKNonBean.saveEdit}" update="@form">
                </p:remoteCommand>

                <!-- <p:dialog modal="false" widgetVar="successDialog" header="Info"
                    closable="false">
                    <h:panelGrid columns="1" cellpadding="2">
                        <h:outputText value="Save data berhasil" />
                        <center>
                            <p:commandButton value="Ok"
                                action="/prpk_paperless/master_prpk.xhtml?faces-redirect=true"
                                onclick="PF('successDialog').hide()" immediate="true"/>
                        </center>
                    </h:panelGrid>
                </p:dialog> -->

                <p:dialog modal="true" widgetVar="successDialog" header="Info"
                    closable="false" >
                    <h:panelGrid columns="1" cellpadding="2">
                        <h:outputText value="Save data berhasil" />
                        <center>
                            <p:commandButton value="Ok" action="/prpk_paperless/master_prpk.xhtml?faces-redirect=true"
                                onclick="PF('successDialog').hide()" immediate="true" />
                        </center>
                    </h:panelGrid>
                </p:dialog>

                <p:dialog modal="false" widgetVar="failedDialog" header="Info"
                    closable="false">
                    <h:panelGrid columns="1" cellpadding="2">
                        <h:outputText value="Save data failed" />
                        <center>
                            <p:commandButton value="Ok" action="#"
                                onclick="PF('failedDialog').hide()" />
                        </center>
                    </h:panelGrid>
                </p:dialog>

            </h:form>
                <!-- <p:commandButton value="Back" style="position: relative;"
                    action="/prpk_paperless/prpk_new.xhtml?faces-redirect=true" icon="ui-icon-circle-close"/>
                <p:commandButton value="Submit" onclick="processSubmit();"
                    style="float:right; position: relative;" icon="ui-icon-arrow-1-e" /> -->
        </p:layoutUnit>

        <p:layoutUnit position="south" size="50">

                <p:commandButton value="Back" style="position: relative;"
                    action="/prpk_paperless/prpk_new.xhtml?faces-redirect=true" icon="ui-icon-circle-close"/>

                <p:commandButton value="Submit" onclick="processSubmit();"
                    style="float:right; position: relative;" icon="ui-icon-arrow-1-e" />

        </p:layoutUnit>