Message Box on Web

We can generate button message with button confirmation using javasript code
and this is example code :

===================================================
< HEAD >
< title >Test Alert< /title >
< script language="javascript" >
< !-- Hide from non-JavaScript Browsers -- >
function ConfirmChoice()
{
answer = confirm("Do you really want to go here?")
if (answer !=0)
{
location = "anotherPage.html"
}
}
< /script >
< /HEAD >
< body MS_POSITIONING="GridLayout" >
< form id="Form1" method="post" runat="server" >
< input type="button" id="btnAlert" OnClick=" ConfirmChoice(); return false;" value="Alert" >
< /form >
< /body >