Question

I cant seem to find the annotation to use that makes sure 2 or more textboxes are the same.

For ex:

public class NewPasswordModel
{
    public string NewPassword { get; set; }

    [MustMatch(Name="NewPassword")] // What is the correct thing to come here.
    public string NewPasswordRep { get; set; }
}

Answer 1

You can use the native CompareAttribute

public class NewPasswordModel
{
    public string NewPassword { get; set; }

    [Compare("NewPassword")]
    public string NewPasswordRep { get; set; }
}