Hi Eli,
Why don't you use sap.m.Dialog as below:
var oAppDialog = new sap.m.Dialog({title:"Document Approval"});
var oDocText = new sap.m.Text();
var oOkButton = new sap.m.Button({text: "Ok",
type: sap.m.ButtonType.Accept,
icon: sap.ui.core.IconPool.getIconURI("accept"),
press: function(){
oAppDialog.close()
}});
oAppDialog.addContent(oDocText);
oAppDialog.addButton(oOkButton);
oAppDialog.open();
Hope this helps.