Calling A Method In A Javascript Constructor And Accessing Its Variables
		 Answer : Yes, it is possible, when your constructor function executes, the this  value has already the [[Prototype]]  internal property pointing to the ValidateFields.prototype  object.   Now, by looking at the your edit, the errArray  variable is not available in the scope of the  CreateErrorList  method, since it is bound only to the scope of the constructor itself.   If you need to keep this variable private  and only allow the CreateErrorList  method to access it, you can define it as a privileged method , within the constructor:   function ValidateFields(pFormID){   var aForm = document.getElementById(pFormID);   var errArray = [];    this.CreateErrorList = function (formstatid){     // errArray is available here   };   //...   this.CreateErrorList(); }   Note that the method, since it's bound to this , will not be shared  and it will exist physically on all object instances of ValidateFields .   Another option, if you don't mind to have the errArray  variable, as a pub...