how to check for null value in javascript

var nameval= new String();
    var name1=document.getElementById("name").value;

it is better to compare the length insted comparing the value of the string in javascript... For example, instead of comparing... if(nameval == null) { // your logic } you can verify... if(nameval.length == 0) { // your logic }

You can simply check the values like this:

if (!myValue) { ... }

 

 

Checks if nothing is entered in the input box

 

if(nameval == "")
    {
    //code
    }