Merge in values from other objects that share the master objects properties.

Object.merge.js

if(typeof Object.merge !== 'function')
Object.merge = function() {
  var base = arguments[0]
      args = Array.prototype.slice.call(arguments,1),
      count = args.length,
      keys = Object.keys(base),
      mergeIn = undefined,key = undefined,i = 0;
    
  mergeIn = function(obj){
    var keys = Object.keys(this),
        key;
    for(key in obj){
      if(obj.hasOwnProperty(key) && keys.indexOf(key) >= 0){
        this[key] = obj[key];
      }
    }
  }
      
  for (;i < count; i++){
    mergeIn.call(base,args[i]);
  }
  
  return base;
}