How to show browser message and on message click event need

Question

In asp.net page by entering the below mentioned code BROWSER is only showing the message but what if i want to ADD Buttons which i created like --> OK and CANCEL and on OK button i have to write some code?

if (isUpdateXMLReportDataSuccess == true)
{
Response.Write(@"<SCRIPT LANGUAGE=""JavaScript"">alert('" + "Bug created successfully." + "')</SCRIPT>");
Response.Redirect("./ManageDefects.aspx");
}
else
{Response.Write(@"<SCRIPT LANGUAGE=""JavaScript"">alert('" + "Bug not created successfully." + "')</SCRIPT>"); return;}


Also here i want to ask that in my case if the isUpdateXMLReportDataSuccess is TRUE So according to code browser first should need to showing the message i.e "Bug created successfully." and then it should Re-directly Redirect("./ManageDefects.aspx");

But in my case it goes to `Response.Write(@"<SCRIPT LANGUAGE=""JavaScript"">alert('" + "Bug created successfully." + "')</SCRIPT>");` but not showing the message on BROWSER and directly goes to Response.Redirect("./ManageDefects.aspx");


ITS NOT SHOWING THE BROWSER MESSAGE.