In javascript object is an entity which can store related data (properties) and behaviors (methods).

The following code creates a doctor object with 3 properties.
var doctor={name:"Dr.Rajeev", age:36, qualification:"MBBS"} ;
We can access data members associated with an object using objectname [dot] property name. Hence the following code displays doctor name, age and qualification's respectively.
alert(doctor.name);
alert(doctor.age);
alert(doctor.qualification);
In javascript objects are usually defined by using curly brackets. Javascript object properties are usually separated by using semi colons. In javascript properties and values are separated by using colon [:] symbol. If a function is associated with an object , the function can be called by using objectname [dot] function-name as shown below.
  <html>
    <head>
    <title>Javascript objects</title>
    <script language="javascript" type="text/javascript">
     var oDoctor= {name:"manasvi",age:5,qualification:"MS",
     getMedicine:function(disease) { if(disease=="fever") return "paracetmol" ; else return "dolo"; }
     };
     function fnTest() {
       //the following code will call getMedicine function.
     var medcineName=oDoctor.getMedicine("cold");
     alert(medcineName); 
    }
    </script>
    </head>
    <body>
    <input type="submit" value="submit" onclick="fnTest()"/>
    </body>
  </html>