-(IBAction)loginClicked:(id)sender
{
    if (![username.text isEqualToString:@""]&&![password.text isEqualToString:@""]&&![companyCode.text isEqualToString:@""]) {
        if ([username.text isMatchedByRegex:@"[a-zA-Z0-9]+"]&&[password.text isMatchedByRegex:@"[a-zA-Z0-9]+"]&&[companyCode.text isMatchedByRegex:@"[a-zA-Z0-9]+"]) {
            ;
        } else {
            UIAlertView *alert = [[[UIAlertView alloc]
                                      initWithTitle:@""
                                            message:@""
                                           delegate:self
                                      cancelButtonTitle:@""
                                      otherButtonTitles:nil] autorelease];
            [alert show];
        }
    } else {
        UIAlertView *alert = [[[UIAlertView alloc]
                                   initWithTitle:@""
                                         message:@""
                                        delegate:self
                                  cancelButtonTitle:@""
                                  otherButtonTitles:nil] autorelease];
        [alert show];
    }
}