private void btnFind_Click(object sender, RoutedEventArgs e)
{
string userid = null;
string fname = null;
string lname = null;
if (useridChk.IsChecked.Value)
{
userid = keywordTxt.Text.ToLower();
}
if (fnameChk.IsChecked.Value)
{
fname = keywordTxt.Text.ToLower();
}
if (lnameChk.IsChecked.Value)
{
lname = keywordTxt.Text.ToLower();
}
dentists = db.findDentistsByOr(userid, fname, lname);
DataContext = dentists;
}