Dynamic Message Base in CP

Summary

Dynamic Message Base creation in Javascript Page

Content

Hello All,

I want to create a dynamic message base in logic.js file. 

The direct message base name given works perfectly.

RightNow.Interface.getMessage("CUSTOM_MSG_EMPLOYER_EXPIRED_MESSAGE");

 

But here I need this message base text in a dynamic way.i.e In this message base the  'Employer' alone will be getting changed in some conditions. I tried in the following ways but no luck. Can anyone suggest me why it is not working or any other way to achieve this.

 

var field_name="EMPLOYER";

RightNow.Interface.getMessage("CUSTOM_MSG_"+field_name+"_EXPIRED_MESSAGE");