Adding options in JavaScript functions that could use later -

i developing small javascript framework, need know how add options function, user can set own settings particular method.

this sample function method have created

$.prototype = {   setcenter: function() {          this.e.style.position = 'absolute';         this.e.style.top = '50%';         this.e.style.left = '50%';         this.e.style.marginleft = '-50px';         this.e.style.margintop = '-50px';         return this;        } }; 

i expecting developed handle below options sets.

*i not using jquery, need pure javascript solution this. example code, maybe not real thing , idea.

$('samplediv').setcenter({               animate:true, fade:true               }); 

help me solve problem, appreciate tries answer this. thank !

you implement main function way :

this.dosomething = function() {     var getdefault = function(args, property, otherwise) {             return args[property] !== undefined ? args[property] : otherwise;     };      this.foo = getdefault(arguments, 'foo', 42);     this.bar = getdefault(arguments, 'bar', false); }; 

so can call :

this.dosomething({foo: true});