Create Pop-Window in ASP.NET using C#

@Kumrvits

First of all your question is a bit unclear,

What do you want to do?

There are Three ways. if successfully logins

1) show an alert dialog box of javascript.
2) Show a popup window which can also be done through javascript.
3) using the below code you can show a dialog

Response.Write("<script type='text/javascript'>alert('Sucessfully login')</script>");
       Response.Flush();

C# also provides to register client side script.

Page.ClientScript.RegisterStartupScript()

For this the below link will help you.


DevCurry.com


Hope you have got the answer

Just a word of warning for you. Pop-ups are irritating, and especially irritating because they are associated with unwanted add. Many users choose to block pop-ups using their Web browser features/plug-ins.
You can develop some alternative presentation for messages. It can be based on some HTML element (typically div) which is normally invisible, so you can control visibility by your events.

—SA

Go there-[ASP.NET Popup Control][^] to read a highly voted article to learn how to create pop-window.
this link[^] also might help you.

you can use a DIV which it's display attribute set to none, when you click the button set it's display to Block.

In Microsoft Visual Web Developer,Paste the following code

ScriptManager.RegisterClientScriptBlock(this,typeof(Page), "Message", "alert('Sucessfully Login')", true);

in your button event you will get OnClintClick.

just write code like this OnClientClick=OnClientClick="alert('Your message')"