Why I have to click twice to show popup, further more how to show borderless popup.

btnPopup.Attributes.Add("onclick", "window.showModalDialog('http://www.yahoo.com','MyWindow','toolbar=no,location=yes,directories=no,status=no,menubar=no,scrollbars=no,resizable=no,width=600,height=300');")

I am new in Web based programming with VB.NET 2005 and searching for advance level articles to improve my programming in this field.

Why we have to take help from JavaScript, Is this tool do not fulfill 100% requirements.

Regards,

Shahzad

string yeni_sayfa;

yeni_sayfa = "<script>" + "window.open('banner.aspx?T=Lavazza Türkiye','yeni','screenX=20,screenY=450,toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=yes,resizable=no,width=586,height=450');</script>";

Page.RegisterStartupScript("JavaScript", yeni_sayfa.ToString());