linq sql blunder message: 'where' found

i'm perplexing start controlling linq personally linq sql nonetheless i'm carrying difficulties

i've attempted sqlmetal controlling database list engineer visible studio i keep removing identical errors, code, controlling information context i combined database plans engineer vs2008.

using system;
using system.collections.generic;
using system.linq;
using system.web;
using system.web.ui;
using system.web.ui.webcontrols;

public biased category _default : system.web.ui.page
{
protected vacant page_load(object sender, eventargs e)
{
    (page.ispostback)
    {
        twine usn = usernamebox.text;
        twine pss = passbox.text;

        (usn == "" || pss == "")
            return;

        dataclassesdatacontext dc = new dataclassesdatacontext();
        var user = u user
                   where u.username == usn
                   name u;

    }
}
}

i an blunder where saying: an doing query settlement source form 'system.security.principal.iprincipal'. also: 'where' found.

i something identical i attempted law sqlmetal. i deleted source started over controlling designer. i contingency blank something here nonetheless i can't figure out what. shouldn't tables exercise i need given i'm controlling linq sql, i need something additional happen?