Methods:
➢ focus(): to place a cursor in a input field when a page get loaded. It can be achieved by combining
focus() with <body> tag’s onLoad() event.
Eg:
<BODY onLoad="document.UserForm.pw.focus()" >
<form name="UserForm">
User Name :<input type="text" onFocus="changeBG()" name="un"/>
Password :<input type="password" name="pw"/>
<input type="button" onClick="checkName();" value="submit"/>
</form>
</BODY>
➢ isNaN(): To check a value is number or not, returns Boolean.
➢