selenium not reading javascript alert in c#

i am using selenium ide for testing my .net website. i am testing login for the website by using selenium. i recorded the steps and as i am testing the code in visual studio the test case is failing. my test case is:

selenium.Open("//login.aspx");
            selenium.Type("fldUsername", "abc");
            selenium.Type("fldPassword", "abc");
            selenium.Click("btnLogin");
            bool log1 = selenium.IsPromptPresent();
            Assert.IsNull(log1);
        开发者_开发技巧    selenium.WaitForPageToLoad("80000");

here username and password are incorrect and is giving a alert. but using selenium it is not getting that alert. please someone help me out..

---

Probably should have been migrated to sqa.stackexchange.com, but, either way.

Is there any reason why you're creating log1. It would be much for efficient to do something like: Assert.isFalse(selenium.IsPromptPresent());

I don't use Selenium 1 much, however, after a quick test, this seems to work.

Assert.IsTrue(Regex.IsMatch(selenium.GetAlert(), "regex to match"));

As for the regex matching, if you're going to make sure that the prompt is there, you might as well make certain that it's the correct prompt.