html form post a username and password to C#

Question

<form method="post" action="login.aspx" name="form1">

<label>Email</label><input class="inputfield" name="userid"type="text"/>

<label>Password</label><input class="inputfield" name="password" type="password" />

<input class="button" type="submit" name="Submit" value="" />

</form>


it is in html page i want to check the username and password for login in c#


how to do these in C# load event

thank u