gistfile1.js

var ko = window.ko;

if( !ko){
    if(typeof window.require === 'function') {
        try{
            ko = require('ko');
        } catch { /*ingore */ }
        try{
            ko = require('knockout');
        } catch { /*ingore */ }
    }
    if(!ko) {
	    return {error:"knockout.js is not used in the page (ko is undefined). Maybe u are using iFrames, if so, browse to the url of the frame and try again."};
    }
}