• Alert Box
• Confirm Box
• Prompt Box

Example of alert() in JavaScript

<script type="text/javascript">  
function msg(){  
 alert("Hello Alert Box");  
}  
</script>  
<input type="button" value="click" onclick="msg()"/>  

Example of confirm() in JavaScript

<script type="text/javascript">  
function msg(){  
var v= confirm("Are u sure?");  
if(v==true){  
alert("ok");  
}  
else{  
alert("cancel");  
}  
  
}  
</script>  
  
<input type="button" value="delete record" onclick="msg()"/>  

Example of prompt() in JavaScript

<script type="text/javascript">  
function msg(){  
var v= prompt("Who are you?");  
alert("I am "+v);  
  
}  
</script>  
  
<input type="button" value="click" onclick="msg()"/>