[javascript] To show error message without alert box in Java Script

Try this code

<html>
<head>
 <script type="text/javascript">
 function validate() {
  if(myform.fname.value.length==0)
  {
document.getElementById('errfn').innerHTML="this is invalid name";
  }
 }
 </script>
</head>
<body>
 <form name="myform">
  First_Name
  <input type=text id=fname name=fname onblur="validate()"> </input><div id="errfn">   </div>

<br> <br>
Last_Name
<input type=text id=lname name=lname onblur="validate()"> </input>

<br>
<input type=button value=check> 

</form>
</body>
</html>