get element by id javascript

Suppose we have a textbox in html and we want to know the value of the textbox then

in javascript we can get the element by two ways:

1.  document.getElementById
2.  document.getElementsByName

<input type="text" id="txtName" name="txtName" value="Mathew" />

function getName() {

    var Name = document.getElementById("txtName").value;

    var Name1 = document.getElementsByName("txtName").value;

    alert(Name);

    //alert(Name1);

}

It will display value in textbox by using “.value” attribute.